Already started a while ago to save everything possible from the JoS, even multiple times and even PDF copies of the pages of this forum that I found particularly useful/interesting.
If you don't know how to do the last one, just right click on the webpage anywhere, click Print, select "Microsoft to PDF" (this may change, just make sure it says PDF) and then just hit Save (or Print) and name it like anything else you'd save in a folder.
Make sure you check it's actually readable as some pages get corrupted in the process and were unreadable, save them again and it should solve the problem.
Hope that helps.