just fyi, typically, you use a chainpunch to seperate the chain, its usually easier than taking the derailleur apart.

my solution to a bent cheap derailleur is to buy a better one I'd probably replace a tourney/acera/altus with an alivio.

oh, re adjustment: see... http://techdocs.shimano.com/media/te...9830604153.pdf under "SiS Adjustment" for how to set one of these up.