I have the Cane Creek bar ends, though they call them stabilizers. Yep, you will probably need to move the shifters inboard a bit. Now, about those grips. . . . Okay, it works pretty well if you can sort of inflate the grips on the bike with compressed air. A regular floor pump works just fine. Now, with the grips removed, remove the plugs from the ends of the bars and put the grips back on. That compressed air trick might be needed, or not, if you're lucky. Now, take the round end of a ball peen hammer and tap the ends of the grips. The handle bars will act just like heavy duty cookie cutters. Now, you've got a hole in the ends of the grips so it's possible to slide the grips inboard far enough to install the bar ends. Sometimes, you do have to sllightly shorten the grips to make them fit.
From time to time, you just can't remove the old grips without destroying them. If you're doing the job on saturday night and planning to ride on sunday, buy an extra set of grips at the bike shop incase you need them, if the LBS agrees to buy them back if they are still in the package.
Well, listen to ol' Rog talk like a pro. I've done this chore exactly twice, but I have done it.
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.