chain from starter to flyweel snap. how do do i take flyweel of if need it to replace the chain? and after i replaced the chain do i have to mess whith timming?  

no you won't need to mess with the timing, their's a timing chain inside the engine connecting the crankshaft with the camshaft, it called the timing chain. you need to remove the starter, left side engine cover, remove old chain, slide the new chain across the flywheel onto the starter clutch, reinstall starter. if by chance you can't slide the chain across the flywheel, and need to remove it. remove the flywheel nut, then using a flywheel puller  remove the the flywheel. flywheel pullers for your engine costs from $10-$15