Replacing plastic back window '01 Boxster's Top

[RZimm1]

The plastic window on my convert. top has a small crack. I seem to have it controlled by clear packing tape. The canvas is in great shape. However I want to deal with replacing the window soon. I've seen replacement plastic window kits for sale on ebay, supposedly to be sewn in by us do-it-yourself'ers. I can't imagine that it's easy to do, especially while the top is still on the car. Has anyone sewn one in? If so how did the project go?

Also I've seen tops with glass windows listed as replacements even for the '01 which originally came with plastic. Is there an issue with the top with a glass window folding up?

Lastly, (for this thread), what should I pay for a company to insert a new replacement plastic window? And if it can be done, what should it cost to have a glass window installed? Thanks all.