Drill them out using a bit slight bigger than the hole, to a depth just beyond the depth of the screw. Place a similar sized dowel in the hole with an epoxy (acraglas or devcon 2-ton). Allow a day to cure. Cot off any excess dowel protruding from the wood. Drill a new screwhole into the dowel, and you are ready to go.
Here's Midway USA's video http://youtu.be/dONmNF2i1hs