I did DIY mine, it was a really fiddly job, first building a flat surface on the back of the aluminium frame to work from, using liquid metal before filing flat and drilling and tapping the fixings. The connecting terminals need the sheathing cutting off and the terminals bending to 90 degrees and soldering the wires on, then cut holes in the steering wheel rear cowl to clear paddles and cut the top 10mm? off of column cowls to clear.
It's a job I wouldn't want to do again, yet if they're the same as I have now, it would be handy if I had a spare pair of paddles, if you want to part with them we can haggle by p.m.