To remove training from a user, we have a few options.
Is the user in a role that shouldn't have received the training? If so, solving this could be as simple as updating the assignment that gave them the learning track in the first place.
If you're an Admin you can go to the Admin Panel, click Assignments, search for the assignment, then edit the assignment and remove the audience that should not have the assignment.
If this user, specifically, needs to have the training removed, this can be done by a Company Admin. To do so, start by going to the Profile tab, and clicking Admin Console (Legacy). From this console, we click on Team, and search for the user we need to locate. Once in their profile, you can click on any learning track to expand it. Then the option to Remove Assignment will appear at the top right of the learning track report.