When the drawer is open, hold the toner cartridge by its handle and pull it straight up and out of the machine.
If any of the cartridges seem stuck and cannot be pulled out, you will need to try using more force or attempt to lever them out. There is no locking mechanism - they should pull straight out.
Are all cartridges affected the same way?
The only way around this is to use more force to pull those cartridges out - there is no other way to remove them.