Did mine the other week, take out the centre panel, fold down the driver or passenger seat back flat(ish) and lean over. I found my normal Draper Allen keys, with the ball ends gets in on an angle on the back bolts. Reach under and undo the nuts...

I am sure it isnt with two able arms, and under 70 yrs of age !!

Live in Stratford upon Avon, Warwickshire.. just come back to Defender ownership and have just bought a 2000 (W) defender 110 utility which I intend to keep so will be spending silly money on it when funds allow. Need to change the fuel pump so...