Fit new seals and try the door, probably wont want to shut. Use blackboard chalk and chalk the door seal, try to close door. Examine door and look for where chalk has transfered and where it has not.
If you lucky, and the chalk transfer is fairly uniform, you will be able to adjust door at the hinges. If the chalk is scattered around the door frame, chances are the lip on the frame that takes the seal will need fettling.
If your really lucky only the striker plate will need adjusted.