Did you get the email from HB about no longer supporting myHB? I believe anyone with a PC could download these now regardless of login or their knowledge of what they are doing. I’m in the SE otherwise I could help you out. I copied some of it below.
Changes to MyHumminbird
One improvement we were able to accomplish was to make it easier for our existing customers to locate and download software updates for their fish finders and accessories. We did this by eliminating the need for customers to register their product(s) and then sign-in via a myHumminbird account to get software updates. Instead, you can now locate all our latest software updates at any time under the Support menu at the top of the page