[Regulus]

I am actually not sure what position will be better.
I removed and refitted it with the window closed, and that made the whole frame easy to handle.
You can connect the wires while the frame is off and lower/raise the window.
Have a look at these photos and see what you think?

Originally Posted by HPsauce

I presume it's necessary to remove the frame first, then take the glass off it, fit to the new frame and refit everything.

That is correct