You will want to remove the finish first, so as to allow the water/steam an easier time of it to penetrate the wood and do its thing.

Plan on steel wooling/sanding the stock if you have a lot of dents, and probably staining the stock.

If you have a stock with uncommon and/or very sharp cartouches, maybe better just clean and oil the stock.

Quoted: Thanks for the help guys.  I had a planning meeting for our FNRA dinner last night but while I was at that my wonderful wife worked on the stock.  The steam trick worked wonders on the dents, the gouges it obviously didn't help any.  This rifle has seen a lot of hard use, losts of deep recoil gouges on the underside and left side of the forearm.  Now I think one more coat of stripper to pull the oil out of the newly raised dents, some bronze wool to smooth things up and numerous coats of tung oil and we'll be good to go.   Thanks again.

If you want to "repair" the gouges, get some walnut sawdust.  This can be had by either sawing up an old unwanted piece of walnut, or dremel tooling an old handguard with the small round ball affixed to the tool.  No doubt your local gunsmith or one of your buddies can help you out.
After that, mix some clear-drying epoxy with the sawdust to about the consistency of peanut butter and apply it into the thoroughly cleaned out gouges.  A toothbrush and alcohol should do the trick in freshening up the gouged material, and will allow for a better bond.
A little sanding and with a little luck, the darker epoxied spots will appear to be knots or small, natural imperfections in the wood.