Hope the link helps you out, if you get stuck just give me a shout as your only 11 miles from me, I might not be an expert but I'm sure with two heads on a problem it'll get sorted, either that or I'll know someone that can!
I have decided to get all the proper cables etc and get help to install it, have removed all my old cables.. Now, whats the best /safest route to go to get to the battery compartment?