Quick fix would be clear packing tape. But you should get an iron and a roll of ultracote or monokote to fix it the correct way.
Also, every few flights or so check your screws and bolts on your motor mount and landing gear. These will come loose due
to the engine's vibration. My front landing gear (nose wheel) came off last nite on landing (I have a Hangar 9 Arrow) so the
plane did a nose plant. The screws used weren't very long and vibrated loose.

Dave...