Get a flywheel puller. It makes getting the flywheel off so much easier. The screws holding the magneto on can be difficult. Lay the engine on it’s side and use good quality #3 Phillips screwdriver. A couple of good hits with a hammer and the screws should come right out. Run a sheet metal screw into the seal and with pliers, pull it out. Put some grease on the inside lip of the new seal and gently tap it in with your hammer.