The M527 printer is shown in this procedure. However, the instructions are valid for the M506 printers.
Press the cartridge-door-release button.
Press the cartridge-door-release button
Open the toner-cartridge door.
Open the toner-cartridge door
Remove the toner cartridge from the printer.
Remove the toner cartridge
Unpack the replacement part from the packaging.
http://www8.hp.com/us/en/hp-information/environment/product-recycling.html
HP recommends responsible disposal of the defective part.
Recycle and unpack
When installing a replacement toner cartridge, hold both ends of the toner cartridge and rock it back and forth 5-6 times.
The M527 printer is shown in this procedure. However, the instructions are valid for the M506 printers.
Align the toner cartridge with the tracks inside the printer, and install the toner cartridge until it is firmly seated.
Install the toner cartridge
Close the toner-cartridge door.
Close the toner-cartridge door