Hello Johan
1. You can go to
joomdonation.com/joomla-extensions/membe...ip-subscription.html
, purchase a new license of the extension to update
2. Then submit a support ticket sending us super admin account of your site. We will help with the update and make sure it's working as expected (update should be OK, but before updating, you should make a full backup of your site so that in case something goes wrong, you can roll back to earlier state)
I want to perform the update myself so that in case there is issue I can check it right away (because you will be updating from a very outdated version)
Tuan