There are two things to you to need to keep in mind before removing someone from a certain workspace:
an employee has to be connected to at least one workspace, so if the employee is only connected to one workspace, it won't be possible to remove it from that workspace. Do you want to connect an employee to a workspace? Read this manual.
an employee can't be removed from a certain workspace if it's the main workspace
in case you need to the remove the staff member from the main workspace, assign another main workspace first in his/her profile under "personal details"
after that, it'll be possible to remove them from the desired workspace
If you want to remove somebody from a certain workspace, proceed as followed:
Go to "Management" - "Users"
Open the profile by clicking on the line of the person that you want to remove from the workspace in the overview.
3. Click on the tab of the workspace you want to remove from the profile.
4. Scroll down and click on the red button " disconnect staff member from workspace".