TA Triumph-Adler P-3020 MFP - Manual (Page 390)

9-6
Maintenance
5 Install the new toner container in the machine. Push
firmly on the top of the container at the positions marked
PUSH, until you hear a click.
6 Turn the toner container lock lever to the lock position.
7 Close the front cover.
NOTE: Return the exhausted toner container to your dealer
or service representative. The collected toner container will
be recycled or disposed in accordance with the relevant
regulations.