I did it on a 1997 +4 short door following GoMog advice & a UK plastics company cut them for me.
I had to break the old units to get them out.
The new ones went in OK.

I still have two halves but they won't fit your car only a short door.

http://www.gomog.com/allmorgan/sidescreens.html#Replacing


JohnV6
2022 CX Plus Four
2025 Renault Scenic Alpine etech "Yvette"