weasel (one's) way out of (something)

To succeed in extricating oneself from some unpleasant or undesirable situation, duty, or responsibility by tricky, sneaky, or deceitful means. He's always trying to weasel his way out of working the graveyard shift, but it won't work this time. The slippery little good-for-nothing managed to weasel her way out of the financial train wreck she left behind at the company. Many suspect the senator used his father's wealth and influence to weasel his way out of the military draft when he was in college.