If you really want to make that seal (or any rubber seal) installation go much easier get some IP P-80 seal lube. It will slide in so easily you'll think you have the wrong seal. In a few minutes it's gone and the seal will as much trouble to remove as the old one.
This stuff looks like plain water but smells good. Dip your fingertip in it, smear it on the seal (it beads up just like plain water would and you'll think this can't work), and immediately push the seal in. Put some on the inside (shaft side) of the seal, too.
For anyone who's ever struggled with getting a seal to install this stuff is the closest thing to magic you'll ever see. Way better than grease, oil, or silicone.
https://www.ipcol.com/products/assembly-lubricants/
They don't sell retail, only to shops (tax ID#). It's not expensive. Can't tell you where I get it, but my brother brings it home from his shop in a tiny plastic pill bottle half full whenever we have any seals to replace. A teaspoon of this stuff will do a dozen seals and half of that will be on the floor. Non-hazardous, biodegradeable, but it is habit forming. If he is out and forgets to bring it, we wait.
We used it on the input shaft seals on my R1100S tranny when the slave cyl leaked and soaked my clutch last fall. I highly recommend the weep hole. It can be done on the bike without removing anything, too.
