Sand the wood molding with 120-grit sandpaper. Remove all of the old finish from the molding.
Sand the molding with 220-grit sandpaper. Smooth the wood surface for the new finish. Wipe down the wood molding with a tack cloth to clean away the sawdust.
Wipe a coat of the new finish onto the wood molding with a clean cloth. Wipe in smooth motions to avoid splotching.
Allow the new finish to absorb into the wood molding. Wipe off excess with a clean cloth. Apply more coats until the finish is dark enough to suit you.
Brush a light coat of polyurethane onto the wood molding. Brush with long strokes to avoid bubbles in the final finish. After the first coat is dry, lightly sand with the 220-grit sandpaper, and brush on a second light coat.