I did this (95 R1100GS), you need one special tool, availible from any auto supply store for around £3 or so- a seal puller. Looks kind of like a thin small pick-axe.
You do NOT need to- remove the exhaust, alternator, front suspension bits.
1. Remove alternator cover
2. Loose alternator bolts (3 of them)
3. Remove alternator belt
4. Remove alternator pully. If it's stuck, but a breaker bar on it, and brace it against the A-arm thingie, and then put the bike in 5th gear. With some help from some mates, push it forward, that will turn the bolt in the right direction with load of torque. You might have to have somebody sit on the bike while pushing.
5. Mark with a knife or chalk, or pen, anything that won't rub off the alightment of your hall sensor, on both the bike and the sensor.
6. Remove hall sensor, three or four tiny hex head screws if memory serves. Put a shop cloth around the sensor, be careful not to abuse it, jostle it, muck about with it. It's sensitive.
7. Take your seal puller, and a small rubber mallet, and gently tap it into the bottom of the crank seal- you want to have the puller parallel to the ground. If you try for the sides or the top of the crank, you won't have enough space to pull properly.
8. Once the seal puller is digging into the seal nicely, pull it out. Try not to scratch the crank or the casing.
9. Take your new seal, and use your thumbs to bend the brown stiff part in, slowly working your way around and around. You need to preform it so that it will slip onto the crank and past the little bump. Patience on this. Most shops rush this part, and then you get a leaky crank seal.
10. Once nicely formed, it should slip on fairly easily, with only a turning to get past the bump bit. Push it in about half way.
THE BEST PART.
11. You don't need any nancy tool for this. Unscrew the rear shock adjuster cap. It's the perfect size to push the seal in a uniform manner. Use the mallet and the cap to very gently and slowly tap the new seal into place. Don't rush this either, make the seal flush with the case.
12. Reassemble. Make sure the hall sensor is perfectly lined up, and that you lever the alternator pully up for enough tension on the belt. I used pliers to clinch the belt, which allowed for the leverage to tighten the alternator bolt.
Sounds like a lot, but with a little patience, a beer or two and some mates, not hard, and should only cost a few quid. The 'book' way costs £100s of pounds at the dealership as they take everything apart. If you move slowly, this should only take about 1-2 hours. With fag and beer breaks.
Email me if you have questions, sorry I don't have pics, my mates can't hold a camera to save their life, and I can't shoot while wrenching, 'cause I'm not that smnart or clever.
Instant no leak.
