Epson GQ-3500 User Manual page 17

Caution
Do not press on the top of the toner cartridge because toner may spill
into the printer. Instead press on the edge of the cartridge as shown. If
toner spills into the printer, remove it with a small vacuum cleaner.
4. On the bottom right side of the toner cartridge are two pins, one at
each end. (See Figure 1-8.) Hold the toner cartridge vertically
with the pins at the bottom and lower the pins into the notches in
the developing unit. Then tilt the cartridge into place, as shown in
Figure 1-9.
Figure 1-9. Installing the toner cartridge
5. Now hold the green toner cartridge lock lever down while you
lower the left side of the toner cartridge. Then release the lock
lever to lock the cartridge into place as shown in Figure 1-10.
Figure 1-10. Locking the cartridge info place
Setting Up