Hello redhead78,
If your question is: "Can a replacement be done?" The answer is a qualified "yes". I have replaced the cabin top hatch glass (actually plastic) on each of the O'days we owned in the past. As I remember the process was not too difficult and only required hand tools and a source of the material you choose to put into the hatch. A painter's tool from the hardware store was a very useful tool for that job. It also came in handy for removing the ports and any deck fittings that we rebedded.
I went to a store named "The Plastic Place" in Fort Myers, FL. Unfortunately, they are no longer located there. The person I spoke to offered the attributes of either lexan or plexiglas. I think we chose lexan, but I'm not positive. Some of the other members will be able to clarify the difference for you.
Bedding the material required a choice of sealants based on the choice of plastic.
Best Wishes on a successful project.