Stock Dent -
The best thing is to take it to a good stockmaker! Be sure you see some of his work. A good gun repairman or a man who is a genius-grade barrel maker on the lathe is not always a good stockmaker.
To do-it-yourself, use google, or your favorite search system, and you can get all sorts of info on refinishing gunstocks. Read up on it and have your "repair" all planned out. The basic fix I've used several times for dents is to cover the spot with a wet cloth and use a medium-hot clothing iron to steam the dent out. The steam will lift the wood fibers, if you are patient.
Go slowly, don't try to lift or expand all the dent out at one time. You might "blister" the wood. Do it two, three, four times, whatever it takes. You'll probably have to spot-finish the area or refinish the stock as a final step.
I am not a gunsmith or a professional stockmaker but, working on a hobby basis, I've done this successfully several times but YMMV! Please read up on the technique and have all the tools and materials on hand before starting.
Good Luck!
GrayBear