We found this article by Troy Griepentrog about trim repair very interesting. You can read more here… http://www.motherearthnews.com/diy/fix-door-trim.aspx
Before we adopted our dog, we tried out a few others from the Humane Society. One of them was nervous and tried to “dig” her way out of the laundry room. In the process, she scratched the trim around the door pretty badly.
Instead of buying new trim, I took the trim from the inside of a closet door. But other than removing old nails and staples, the process is basically the same if you were to buy new trim. To get the angle cuts right, use the old pieces as a template.
Start by prying the old trim loose with a flathead screwdriver or pry bar. As you pry the trim loose, insert another screwdriver or pry bar in the space where the trim is tightest. Work gradually along the entire piece of trim. It’s a good idea to use a piece of scrap wood or cardboard to protect any surface you pry against.
Remove any nails or staples from the frame and trim. Note where there is something to nail the trim to. There’s usually a gap between the frame and the wall.
Attach the trim with finish nails (small nails with small heads). Before nailing the new piece of trim in place, you might want to drill small holes for the nails to prevent the trim from splitting or cracking.
“Set” the nails. That simply means pounding them below the surface of the wood with a tool called (appropriately) a nail set. If you don’t want to invest in nail set, a large, stout nail will also work.
Setting a nail
To finish the project, cover the nail holes with matching wood putty. You can simply spread it over the nail holes and nail heads with your thumb or finger.