I put mine on with Pedro's plastic levers. The first time I did it, it seemed absolutely horrible. However, since that time, I've done this many times:

1. After you ride them a bit, they are easy to mount and unmount.
2. When you have new ones, it helps to kind of let the air almost completely out of the tube (after you have have it positioned correctly...). It might help if the tire wasn't cold. And you kind of have to ease it on, without trying to risk breaking the lever.

However, a factor in this is the rim you are mounting the tire on. Some are easier than others.