My kitchen DG window has moisture inside. The unit was fairly recently removed and re-fitted, so an adjacent door could be renewed and the guy didn't seem to make much of it but I didn't watch him.
I can get a replacement unit for less than £100.
It's secured with a triangular external plastic fillet, which obviously has to be unclipped and for which I bought a purpose made metal 'chisel' but looking at a Youtube video, I get the impression you have to remove the inner rubber gasket first. Is that correct and if so, how?
TIA