String so clocks rubber seals, on both install and removal. Feed a 5mm or so string into the same place those metal plates are sitting. Then just push it out. For install, push the string into the same part of the seal while its out of the car. Sit seal in place and push it in nice and snug. Then just pull the string out. It will, with a bit of help, refit itself around the frame.
Crack a beer or two and marvel at how amazingly simple the job was.