Dropping timing chain into lower engine on ttr 125 01?

hi i took my head off to take it to a machine shop and i got it back and i went to put the head gasket on and i dropped the timing chain into the lower engine. i wouldnt have a problem but i cant seem to get my left transmission cover off, it seems to be siliconed together and it just wont budge. ive tried to hammer the flaps and it wont move a inch. please help! why wont it move? how do i fix this problem so i dont have it in the future. btw i cant take it to a shop