Man that stock looks good. I really like the checkering.
The only laminated stock i ever reshaped was unfinished. It was for a 10-22. I cut down the foreend on a band saw, reshaped the thumbhole with a coarse rattail file, and reshaped the butt to accept a mini 14 style recoil pad. The latter took a little work as I had to make a special fixture for it to run on a router table. I also pillar bedded the take down screw, and glass bedded the receiver and first two inches of the barrel (all that was left by the barrel when I was done cutting the stock down actually).
If you draw the lines you want to achieve on it in pencil (make sure you use pencil as ink will soak into the wood and make for more sanding, or possibly bleed ut of the wood and ruin the clear) and start with a coarse rattail (I guess it depends on how drastic the change is), it will cut fairly quickly, then sand to a smooth finish. As I said before though my stock was unfinished. I thinned polyeurethane with mineral spirits and brushed on four coats of high gloss.
I'm sure someone with more experience than me can tell you how to match the finish.
