removal of gts rear light cluster

anyone done this? looks a straightforward job, access through a hatch the boot cubby holes, 2 push fit connection blocks and one nut

Need to replace the cover and am feeling to tight to pay the garage labour, plus the hastle of going to the garage and the likelihood that i'd need to tighten something up any way

Just thought I'd check before embarking on a seemingly simple job and making a hash of it!