ya know .. I was doing this the other day and I realized that you dont even need to force the alternator in there with a Hammer. If you look while the alternator is out, the bushing gets pulled past the Ear on the bracket. Grab a hammer and a punch or something hard to hit against that bushing. Place it on the inside side where the alternator normally sits and hit towards the passenger side. The bushing will go flush, and the alternator will fall inside the bracket.
I've always just whacked them into place, but this method of using a punch is WAY easier. You can even get it without using a punch. Just using the hammer.
Heres a picture of what im talkin about