Yes, you can move an owned license of JEM at any time when you pay the owned license price. Once that is done, we can cancel the recurring payment for the leased license without affecting your current JEM site install.
There is no need to reinstall anything. All changes happen on our site, nothing changes on your site.
a leased license requires you to pay a small fee each month to keep your license active for your site. This is similar to a hosted license, except that you host the software on your own hosting account.
An owned license only requires one payment for the software. Once that payment is made, you own the software free and clear, with no other required payments in the future.