dvdegeorge has it very well covered. The only things I do different is when I remove the nipple, I also remove the bolster clean out screw on the side of the bolster (if your rifle has one).

After the hot soapy water bath, I then take my barrel outside and pour about a coffee pot full of hot boiling water down the muzzle of the barrel, letting it run out the nipple and bolster clean out hole. Then get a glove or towel and grab the barrel and bring it back to where you are cleaning it.

Here I dunk a bore brush in solvent and I work that up and down the barrel at least 15 strokes. It will amaze you, what that bore brush will knock loose in a hot barrel. After that I run solvent patches up and down that very hot barrel. They will finally come out clean.

Then take a pipe cleaner and poke that down the nipple hole and into the bolster clean out hole. Then I blow down the barrel and run dry patches until they all come out bone dry.

After that I run a patch with some quality gun oil such as REM OIL or Birchwood Casey Sheath on it to coat the inside of the bore. Next I put a little dab (and I mean little, you do not want to cover any flash hole here) of anti seize compound on the threads of the bolster clean out screw and the cleaned nipple. I then replace them.

I then take some Q-tips and dunk them in solvent and scrub around the bolster and nipple area of the rifle getting all the fowling off from inside and under the bolster until the Q-tips come out clean.

After that I wipe the barrel off with the same patch I ran down the bore of the rifle and re-assemble the rifle.....