which fire extinguisher?

Yup Long as it's an ABC you're good to go. Do you have compressed air? I have removed a LOT of rivets and the easiest way I found is, take a die grinder with a cut off wheel and cut a + sign in the rivet head. Then come behind it with an air chisel and cut each quarter off. Swap out the chisel for a punch and drive the rivet out. This takes literally only minutes per rivet.