Is it possible to bleed a radiator without the bleed screw?

I have a radiator upstairs which has a brass bleed screw at the back which is totally rounded off (previous owner). It is impossible to move with a pair of pliars and I have tried filing it back to a square end but its so soft i still cant get an adjustable spanner to move it without rounded it off. is there a method i can use to refill the system which might move the air either out of that radiator or move it to another one where i can bleed it? I am thinking along the lines of refilling the system in a certain order or shutting all of them off except the duff one and letting that fill up and then shutting that one off and refilling the rest. Is this possible?