I have SLP ultra lite bars with ODI 8" grips and I love the way they feel. To remove the stock grip simply take a razor blade and make several shallow cuts across the grip and then rip it apart.
If you have not put hooks on the bars there should be a little hole in the end of the grip put a air nozzle on a compressor in that hole squeeze the trigger and hold it down and the grip should just slide off.
To remove the stock heaters from the bars you will just have to peel it off and be careful not to rip it!!!! If you do rip it you will just have to but a new one not a big deal!!
I know SLP makes what the call a cushion grip so you might want to look at that if you want something softer!!
DW