I wouldn't mess withe recoil pad. For one, I don't think it's solid rubber, and two, that thickness helps a lot to keep felt recoil down.
What the smith will probably do is a cut a bit off the end of the wooden stock. Your friend could probably do this himself with a good saw, but the smith will likely do a better looking job, unless your friend is experienced with wood working.
If your friend wants to do this himself, he should check on the internet for instructions on determining the correct length of pull, then subtract that number from the current stock's LOP to get the correct number of inches you have to remove from the rear of the stock. Make sure the cut is made squarely with the original cut, remove the wood, and then remount the recoil pad after making any necessary finishing touches to the wood.
Alternatively, you could probably find a replacement wood stock with a short LOP, but wood stocks can be expensive, and likely costs more than having a gunsmith change it for you.