Header Nut Removal

[Gila One]

'87 GN - trying to replace turbo to header gasket. 2 of the 3 stud nuts presenting problem. Hard to get leverage on wrench/socket. Looking for advice on tool to use, heat/no heat, anything else that will help me free those nuts up or better to remove stud and nut as unit?

 

[John Larkin]

Lots of PB Blaster and consider going through the wheel well for additional access. Back stud and nut out together if necessary. Better to do that than snap one off.