You can get all things done in Colon, but here are instructions how to get it done in Panama City (reserve one day for this):
– First thing you need to do is to get your bike inspected. You can get it done in N 08°57.998’ W 79°32.697′. Go there in the morning at 8am (red door). They stop doing inspections at 11am. You need to have a copy of your passport, title and Panama customs form.