Just changed the ones on my '09 from orig. grips. The stock clutch side grip was not glued on, and the new H-D chrome and rubber would only correctly fit in the switch housing one way.

 

Ahhh... OK, I re-read the OP's original post = "aftermarket". With HD grips, the clutch side mounts under the switch housing into a slot that requires the grip to go on only one way. The instructions with the HD grips call for that side to be counted first, and then the throttle side, since the throttle side can be positioned in a number of ways.

 

I will state the obvious.

Put a towel on your gas tank whenever you are mucking around with anything above it. There is nothing worse than dropping a screwdriver on your perfectly polished tank.