I'd try lifting the rear seats or carpet above the tank, should be an inspection cover that can be removed, you should find the sender unit lurking on top of the tank, it may well be held on with some sort of screw on fitting so a bit of applied force may be needed to undo it (daresay LR dealers have a special tool for this), once you get the sender out a simple siphon operation with some 1/2" pipe will soon have the fuel out.

Might be worth having a look underneath the car, see where the filler pipe enteres the tank, you might be able to remove the pipe from the tank and feed the siphon pipe in there instead.

Another way, if you can get your hands on an old electric fuel primer pump, you might be able to connect the pump to the supply pipe from the fuel tank at the engine end and pump the fuel out, that will take an hour or so.

Obviously you'll need to clean out the rest of the fuel system as best you can if the engine has been run, all depending on the wrong fuel ratio.