Tongue-and-groove boards interlock, which can make it difficult to repair a small area -- releasing one damaged board would mean releasing all the boards. Instead, use this patch method to replace just the damaged board.
Before Yet Get Started
Where the damaged board crosses furring strips on the wall, it may be easier to use a hammer and chisel to cut through the board.
If the board is very thick, remove the tongue with a saw.
If you want a natural wood finish, consider using an adhesive to secure the board in place rather than using nails.