Cleaning Stained Glass

I have a beautiful piece of stained glass on my top floor ceiling below a skylight but it is so filthy, barely any light gets through. The skylight is sealed and bolted shut. How do I access the stained glass to clean it?? Does anyone do this professionally? I saw a similar post on this site a few years ago but there wasn’t a satisfactory answer.

Thanks in advance!

By lbm |