"1. Carefully mark and cut the necessary amount off of your grips to give room at end of bar to clamp on bar ends, "

I'd take this advice carefully. If you have small hands, this is OK. The first set of bar ends I installed in like '89 I cut the grip width down. After the first ride, guess what I did? Bought a new set of grips! Most grips are just about the perfect width. Slide all of your controls inward on the bar, making room for the clamp on the end of the bar. And if it turns out you don't need the extra width of the stock grip, you can always cut them down later. But once it's cut, it's cut!
Good luck.
PS Why is it completely uncool to ride riser bars w/ bar ends? Talk about a way to receive unending ridicule on the trail! What got this idea started? I thought form was supposed to follow function.
I'll never use riser bars - I absolutely cannot go without bar ends. Best thing since sliced bread and clipless pedals!