So to remove the fuel tank you need to do the following.
get the car as high as possible- life is easier
disconnect the main fuel line - turn the bolt on the hardline. Disconnect the return and vapour lines.
2a) disconnect the harness plug from the fuel pump hat - accessed through the boot.
drain the fuel from the plug on the bottom of the tank (not required but makes life much easier and less fuel to spill)
disconnect the filler neck feed and vent tube
the tank is held on by 5x 17mm bolts - undo these slowly making sure the tank is supported- I used a trolley jack and a plank of wood.