Need Help Fitting Rear Strut Brace

[cHinGy]

I bought a rear strut brace for my t sport.

Took of the 2 cover on the side of the boot that was hiding the nuts.

With a one of those hexagon 15mm rench, the nut keeps on turning but doesn't wanna come off.

There's two nuts, one on top of each other, below there is a silver disk. Everything turns when turning the nut. Even the black screw that the nuts are on.

Any ideas on how to get the nuts off?

[cHinGy]

Never mind, just realised you had to hold onto the bottom nut with a wrench and undo the top with a socket.