Right, I had a go last weekend, but it didn't go very well: I dropped out the spare wheel (for my head so I could see!! So I could see!!!!

) & undid a couple of bolts to offer up one of the inside brackets.... which was promptly too large for the bumper bracket it seems to need to fit inside. I didn't have a go of 'persuading' the bumper bracket to expand a little to fit. It looks like removing the bumper is the best option.
So, how do I do that, then?
Thanks.