I am not saying go out and do it on your own your first time with no help, but its a nice skill to know. Have someone that knows how do it, but be there and watch them and learn all you can. I was scared of gear installation, but after I helped a few times, its not to hard. The main things to watch are backlash, should be somewhere between .008-.012, and pinion depth. To set backlash, shim the carrier right to left. Make sure what shims you remove from one side, you put back in the other, example, if you remove .005 from the right, put .005 back into the left side, you have to use a dial indicator. To set pinion depth, shim the pinion gear up or down to ride in the ring gear properly. Just note what your stock gears where before you remove them. If the stock gears had .009 backlash, and the pinion was in the center of the ring gear, set the new gears the same. Its very time consuming, because you may have to press the pinion bearing on and off many times to change shims. Make sure you install a new crush sleave. You will never learn anything, if you have someone else work on your car. Just my .02.