The cams will either be stamped with the nomenclature "EFA" or "ESM"... the EFAs are the speed mods; the ESM are the smooth mods. There will be a number following that such as 2 or 2.5 which corresponds to the draw length. When you change out the mods, you have to adjust the draw-stop peg accordingly.

The draw mods are located on each cam, and can be swapped out with the removal of two Allen-head screws once you determine which draw length you need, if different from what's currently on your bow.

And yes, I'd suggest taking the bow in to your dealer for a proper fit. He can also order you the correct mods that you'll need, if you need to change them out. He will also have the chart showing where to set the peg upon switching out the mods.