To release an eaDocX floating licence for use by other users, just close-down all the eaDocX windows which you have open in EA. As the last one is closed, the eaDocX floating licence is made available to other users.
Sometimes, users may not shut-down eaDocX in a way which releases their licences.
All eaDocX licences have a timeout, which automatically releases the licence back into the pool after a period of time.
This is usually set by eaDocX at 30 minutes, but can be made shorter or longer by request. Note that this timeout value is encoded into your eaDocX Floating Licence, so changing it from the default value will mean re-issuing the licence key, and re-distributing it to all your users.