Rad Support bolt question ?

[Southern Shaker]

Hey yall,

I need to swap over my rad support and it has new mounts under it already got one free but the other one wont budge at all i mean i shot it with pb blaster an everything its tighter then me in a pair of levi's the whole mount spins but the nut will just not give way i cant seem to get any leverage to stop it from spining when i turn it to try an bust it ..anyone have a better easyer way ? P.s i aint got power,air out here so its wrenches an hand tools

Thanks in Advance -Aden