The short story is that I need to remove/replace the fuse/relay box in the engine bay - have loosened the bolts, but there appears to be more to it - any hints/tips tricks?

(the slightly longer story - had been traveling on business for 2 months, hopped into the car and she turned over fine but wouldn't start. After popping the hood I could see that a rodent(!) had gnawed through the side of the fuse box and chewed through a few wires underneath. Car has 135,000 miles and this is what brings it down? lol)