The following is an explanation on how to update Shoe Last Maker.
The first step is to obtain the latest version of Shoe Last Maker in the form of an rhp plugin file for Rhinoceros 3D. You can do this by either purchasing a new version or, if your subscription is still valid, logging in at https://ShoeLastMaker.com/wp-admin with the credentials provided and after that, following the link on the next line (visible after logging in with a valid subscription)
There may be a shorter way to go about this. Perhaps just dragging and dropping the new file might work for some. But the above is sure to work.
If you ever want to check to see if your current version is up to date, right click on Shoe Last Maker in the plugin manager (command ‘PluginManager’ to open it). This can be compared to the latest version number mentioned on the main download page.