If you have restricted the number of device login limit per user, the users won't be able to sign up with any new device once that limit is reached.
However, if the user want to remove the login from any existing device and replace it with a new device login, the admin has the right to make those changes through the course platform.
Steps to reset User's Login Device:
Log in to your institution panel and head towards "Dashboard". Now, scroll down, select "USERS", and then click on "Learners".
In the landing page, you will have the the cumulative list of all the learners who have signed up for any of your courses.
Go the learner whose device you want to reset. You can either "Search" their name or Email id in the search box or apply multiple filters and click on "Search".
Now choose the learner whose device you want to reset. Under Actions, select the "User Details" icon.
In the "User Details" landing page, scroll down till "Login Details". Go to last app logins or last web logins & delete the devices which the user no longer want to be connected to the course platform.