I have the Ergon GP2 and they are flat feakin AWESOME! Excellent wrist support and additional positioning helps
To remove old grips: take your thinnest allen wrench and, if you need the assist, isopropyl alchohol. Insert allen between grip and bar, lean bike handle a bit downward, and dribble/splash in a little alcohol. Keeping allen in, rotate gently around, then twist off the grip (should be easier now).

When putting on the Ergons, place the cap end on the grip before putting grip on the bar. Slide onto the bar till the cap end just starts to back out of the grip. Push the cap end into the bar. Holding one palm against the cap, push the grip back, all the way, against the cap. It will now be exactly at the end of your bar. Rotate where you want and tighten.

On my commuter....
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Be sure to get the right grips according to your shifters (grip shift/trigger shifters).