Hi,
mine is in green. Please note that everything you do is on your own risk.
1. Take of the steel plate.
2. pull out the blue LED
3. put in the green LED
4. Mount the steel plate
That´s it !
It could be helpful to have some glycerine for the mounting. Use ist on the fittings for all the curves inside.
I don`t know, how to get the Plexi of!
The plexi is fixed with a small screw. No glue anyway.
Cheers
Stefan