Oki MPS711c User Manual page 88

9. Insert the left end of the cartridge into the top of the image
drum unit first, pushing it against the spring on the drum
unit, then lower the right end of the cartridge down onto the
image drum unit.
10. Pressing gently down on the cartridge to ensure that it is
firmly seated, push the colored lever towards the rear of the
printer. This will lock the cartridge into place and release
toner into the image drum unit.
88
b
– MPS610c/MPS711c User's Guide
a
c