HP Deskjet 3820 Color Inkjet Printer - Manual (Page 51)

replacing print cartridges
Before buying replacement print cartridges, verify the correct part numbers .
When a print cartridge is empty, leave the empty print cartridge in the print cartridge
cradle until it is replaced. The printer requires both print cartridges to operate.
Warning! Keep both new and used print cartridges out of the reach of children.
To replace a print cartridge:
1. Verify that the In tray is down.
2. Press the Power button to turn on the printer.
3. Open the top cover.
The cradle moves to the center of the printer.
4. Raise the cradle latch.
5. Lift the print cartridge out of the print cartridge cradle and discard it.
1. press Power button 2. open top cover
3. raise cradle latch 4. lift print cartridge out of cradle