Oki C3520 - Manual (Page 117)

Installing additional memory > 117
3. Press the cover release and open the printer’s top cover
fully.
4. Remove each image drum units, starting with the front.
Cover the image drum units to protect them from direct
light
WARNING!
If the MFP has been powered on, the fuser may be hot.
This area is clearly labelled. Do not touch this area.
a
b