How To Bleed An E34 Radiator

[j.leggz]

hi there,

on friday of last week my radiator decide to die,

i picked 1 up yesterday after being told it was a 520 radiator i then found out later it was off a 525, a year newer than mine, it is about an inch shorter than the 520, dont know why,

ive been pumping the hoses and am trying to remove a big airlock, when i put the cap on the radiator it still pushes water out of the top, it also sounds like its really boiling up in there,

can any1 tell me if there are any bleed nipples anywhere where i can lose the airlock from,

i know jack all about cars and even less about bmw's

thanks in advance