header flange fix

hey guys. wondering if anyone knows any home garage tricks to straighten out a slight curved header flange? the front collecter on the passenger side is ever so slightly not level when i checked with a staight edge. definetly had a header leak since i put the headers on (soot all over the heads when i pulled them off for porting).
if there is no home tricks, does anyone know of a reputable machine shop downriver/monroe area i can get them ground level?
thanks guys

The only homegrown trick that I have known to work is to cut the flange between the front tube and the center double tube so that it's seperate then the bolts can pull the flange and tube flat to the head, maybe.

im just real paranoid of stripping the head bolts out. damn these headers...lol