Can you share please? I've got same problem.
You need to get your head around standard format kit Boner & not worry so much.. any basic net search will drag up a plethora of videos (varying quality) that will get you round what is essentially a 2 wire fitment on millions of cars regardless of brands.
took me less than 10 seconds to find this..
& whilst that isn't your rear trunk / boot specifically, its actually more of a job, you just need to break it down into relevant info bytes & apply yourself
there is less to get in the way in the boot area where you wish to work.
Honestly you can do it.
Thing is, there are so many trim items that need spudgers to lift / tease free items within a car interior, a good set is nigh on critical if you intend on "fiddling & tweaking" any vehicle in your possession.
& as a brucey bonus, (as a lot of folk want integrated USB where once a cig power socket existed ... another video to think on & then proclaim, "same fitting, just adapted" (with a drop in same size replacement, because ..as already stated its an industry wide part.
Baby steps, & a clinical approach will see you through, let us know how you get on
, the panel in the boot / trunk of the mini is just a basic covering, the old unit should tease out (be careful around live wires naturally) spade connectors are as simple as 1,2,3...