Every time I update my Helix, I am a little bit nervous. Every time I follow the advice from datacommando and read the release notes and follow instructions to the letter. Every time it has worked.
The release notes talk about update from versions earlier than 3.15, and datacommando says it can be done. I haven't done this myself, but that would be good enough for me to attempt it.
As the release notes say, back up your presets and IRs first, and make sure you are working from the latest release of HX edit. Don't panic when you get the boot error message - it's normal, the release notes tell you to expect it when updating from firmware earlier than 3.15. Don't panic - it does take a few minutes to continue, and I confess it made me nervous and felt a lot longer than it actually was when I did the 3.15 update. Don't overlook the factory reset which will indeed clear the Helix - that's why you need the backup so you can restore - make sure that the restore is sorted and covers everything you want to keep before you update.
Even if the worst happens, and theres a power interruption or some other unexpected problem with updating via hx edit, datacommando has posted step by step instructions on how to recover. Thanks datacommando - knowing your advice is there if I need it has been a great reassurance for me and I suspect many others who don't post too often.
Most of all - glad you're back to guitar and helix - hope you get to enjoy playing some more!