Before you do that, do you research! I paid somebody to do my gears last time, but I really want to learn the innards of an axle real well just because. There is a great read/procedure below for doing your own. The down side to doing your own is, is that you warranty your own stuff. Screw it up once and you pretty much paid for somebody else to do it.
If your gears are 3:07, which I'm sure they probably are, you will need a different carrier to go to 4:56. Are you using new gears or used gears? You will also need a master rebuild kit and some specialized tools. That is the VERY SHORT version. Most people will tell you not to. Whatever, it's your Jeep, but know the consequences if you screw it up!
AND....good luck lol.