I just did this... I removed the expansion tank. It is sitting directly beneath it. The fuse block is plastic. It connects to a metal frame with hex heads. Then the metel frame sits on bolts of its own on the firewall and is connected with 10mm nuts.
I cant get the nuts off the fuse block wires though. I had cut and put on a new end terminal for the main battery lead, but I can't get the old one off because the nut is seized on the bolt.