seized double glazed top opener on window

[claretnproud]

replaced 2 window handles today . got the 3rd handle off and fitted a new handle but it is siezed solid. the window is locked but in that position that allows air through. even when I insert a key steel and try to turn it with mole grips its not having it. I have sprayed wd in the key steel hole. Its an upstairs window so difficult access from outside. any ideas on what else to try without having to replace the unit?

[Bosscat]

Looks like the mech has gone m8...

Get a window specialist out....