While in Google Meet click the People button
Click the Drop down menu arrow next to the student that you want to remove.
Click the Remove from meeting button.
Click the Remove button.
Note - Once you remove the student they will not be able to join again until you reset your Google Meet link.
Go to your Google Classroom
Click the COG (Settings Gear) in the upper right corner
Scroll down until you see Meet
Click the link to the right of Meet and Click Reset