96 200sx Drive Axle seal installation--help

[pawdrip]

Could anyone lend me their insight into the replacement of the 2 drive axle seals. I have a 5 speed, 1996 200sx 1.6 engine. I had to replace the ring gear and therefore pull the half shafts out. Here are some of my problems:

1. The seal I got from Nissan dealer does not look exactly like the one I took out. Have then changed them

2. What is the orientation of the seal to the engine side and the wheel side.

3. Do you have to use a special tool to do the installation?

4. When installing does the seal bottom out or do you have to leave the lip exposed a certain distance.

Any help I could get I would greatly appreciate.

thanks