Hook the new one to the old one with the coupler and use the crank and very slowly feed it in and take the old one out as it comes around. A piece of baling wire on the free ends will keep you from dropping it into the engine.. There is no timing issue but the new chain must be tensioned properly acording to the Mechanics manual.. If you have removed the old one already , its a bit more tricky.. You must slide a yardstick in the st/gen opening and then slide the new chain on in and grab it with a hooked piece of wire and thread it thru.