Fortwo Battery Removal
Using a 10mm socket, remove the nut from the stud.
Lift it up and it will unclip from the other end.
Unclip the main live cable from the holder.
Using a 10mm socket, remove the earth connection from the battery.
Then remove the live connection.
The battery is now free to be lifted out. Be carefull, they are heavy and dangerous.
Thanks to Ian for the info.
Place the new battery in place and refit the metal strap and bolt down securely.
Refit the live connection first ensuring it is tightened.
Then replace the earth cable, again making sure it is secured properly.
What Battery Do I Need?
Here is the info for what replacement battery to get.
Don't buy one from Halfords, if you are a member of Costco, buy it there.
If not, ring around a few local suppliers, you should to be aiming to pay about £35.