I found this on another forum:

I usually replace buss first, then string. Start with bus and string already twisted at the correct number of turns. When mounting the string, you have to be careful that the crossover isn' t touching. This is where the string is mated to the cable guard slide. Before loading the bow be sure that the end loops are fully around the cam studs and not able to slip off. Also check to be sure that the string and buss are fully seated in the cam and wheel grooves. Put your peep in now. With everything looking good, slowly release your press and gradually watch the string/buss load. If there are problems, they' ll show up prior to total release of the press. All solo cams are similar and having another bow handy to look at while your doing this can be helpful. Use care, go slow, and triple check everything before loading the limbs. The most common errors are string crossover, incorrect twist rates, and sloppy wheel/cam string mounting. Eliminate the possibility of these errors before adding weight to the limbs and you' ll find it' s a fairly easy job.

Step one, gather all manufacturers specifications on your bow :
Brace height , axle to axle length, specified string length and specified cable length.
Step two, take measurements of your actual brace height, axle to axle length , nock height peep height ect. Write it all down so you can reset everything after you change the string and cables.
Step three, mark the rotation on your cam by striking a mark
with a pencil on one side of the cam, parallel to the limbs on each side of the limb. This provides a reference for you reset the cam to proper rotation by twisting or untwisting the cable or string or both .
Step four, Make a rough sketch of your bow, cam , idler wheel and cable roller guard showing the string and cable tracks and the route they take including crossover point and cable roller slot location. It doesn' t have to be pretty , but it will help you remember how the string and cable goes back on.
Ok let' s Rock !
Take a few turns off the limbs to lower the poundage and press the bow down .
Change the cable first while leaving the old string on the bow . (Keeps it less confusing that way for a newbie string changer. )
Remove the old cable and just for giggles measure it' s length and compare it to the manufactures specified length . This will give you an idea as to whether or not your bow was within specifications when you started.
Now take the new cable and measure it' s length and see if it matches the manufactures specs. (This is usually where the twisting comes in. ) You will want to adjust the cable by twisting or untwisting it until it measures just short of the specified length ( about 1/8" to 1/4 " short since there will be some stretch when its under tension on the bow .)
Route the end loop of the cable through the cable roller and attach it to the cam post and route the serving in the cam cable track as it was . Now that you have the lower end of the cable installed , put a few twists in each side the " Y" yoke and install it on the cable hangers on the top axle. At this point check the cable for fit by backing the press off, being careful that everything is in place in the cam and idler tracks . At this point you will need to check the tension on the upper cable " Y" yoke and note that one side probably needs a few more twists in it to equalize the tension. Press the bow back down and install the twists to even the yoke pressure out. . That should about do it for the cable Installation at this point.
Press the bow down again and remove the old string . Once again I like to measure the old one to compare it against manufactures specs and see if much stretch had occured .
Lay out the new string and measure it off . (I usually hook one end on a nail and then stretch it out.) Adjust the new string to to a length just short of manufactures specified length by adding or removing twists, just as you did with the cable ( 1/8" to 1/4" short .)
Feed the correct " end loop" through the lower limb fork and feed it around the cam track and hook it on the cam post. Now route the serving around the outer perimeter of the cam over the string suppressors, around the idler wheel , through the limb fork, down through the roller guard and finally around the remaining cam track and attach the end loop to the cam post.
Examine everything on the string track routing and compare it to your memory and the " all important sketch" that you drew at the beginning .
If everything is cool, Throw your peep back in the string and then back the pressure off the press and put then turns back on the limb bolts to bring poundage back up .
Now measure your brace height and axle to axle length . Compare the marks that you made on the cam to be sure the cam rotation is close to where it was . If you did the job properly everything will be very close to the where it was when you started.
If cam rotation or the Brace/ ATA specs are off a little, you can correct it by adding or removing twists to the cable and string as necessary However you should shoot the new set up in with a couple of hundred shots before worrying about making any final adjustments. Once you shoot the new string in, then set your final nock height and serve your peep into position.
The number of twists you put in the cable and string will vary depending on the actual finished length of the cable/string .
It would be nice if all string manufacture' s produced strings and cables that met exact manufactures specifications , but alas , it isn' t so !
It is good to put quite a few twists in the system , because that will reduce peep rotation .
At the local shop we start with about 14 twists in the buss cable and 40 twists in a standard single cam string, then measure them for length and add or subtract twists as needed to meet the bow manufacture' s specified length. As long as you meet the bow' s specified string and cable length, the draw length and poundage should be right.
A word of caution on " Zebra " strings is that they recomend that you add NO twists to them, because of the counter rotation of the string bundles . If you add twists, it will actually untwist one strand bundle as it adds twists to the other strand bundle. That will cause and unbalanced string.
Most other strings don' t have this problem because the strand bundles are twisted the same direction when they are manufactured .
There is no set amount of twists on string and cables , as the number will vary according to string/cable length and the individual bow. It' s just something you have to play with a little to get just right!

I hope that this helps you out, and answers some of your questions.
Charlie