The way it works is quite interesting, David is correct "Now that GMS2 (Trial Version) is free for educational establishments".
When you buy as a school you get a "Seat Manager"
You have to buy at least 5 seats, for example, but 5 seat licenses of "Desktop" the Windows version
In your seat manager, you will see 5 seats listed.
You create a username and password an assign it as a student login aka as a seat license
Under the students log in info in the Manager is a checkmark representing the access to the pro features
If you remove the check mark next to the desktop seat the student license reverts to trial.
You do not have to delete the license or the student, you can just assign this released license to another student in your manager.
This system is amazingly easy to use. I have dealt with AutoDesk, Camtasia, and Unity where you had to license via a network server or a machine. Students could not use their licenses except on the one workstation at school. With GMS2 the student could be anywhere, and you can turn on and off seats with the click of a mouse.
The only problem I have come across is created by the student themselves. The student logs in on a workstation they must remember to log out if they want to work on a different workstation using the same login. They can log out to free it up, or delete the seat and create a new one within the limit of your purchase.
I love the new system. I just wish it was a little more affordable for a nonprofit or a public institution that has limited funding.
I have had very little technical issues, one workstation required a reinstall since I started using GMS2.