How to Increase the Memory of an HP Laserjet 6P

Push the 'Go' and 'Self Test' buttons on the LaserJet 6P control panel simultaneously. The printer prints a test page showing the current configuration. The configuration shows any expansion modules for fonts that are currently installed. Turn the printer off.
Remove all cables from the back of the LaserJet 6P.
Press the latch on the right side of the LaserJet 6P to release the top lid. Lift the lid of the printer.
Press the latch on the left side of the LaserJet 6P to release the cover on the left side. You should see two indicator arrows next to the release latch. Pull the cover toward you until the two arrows line up, and then lift the cover off of the LaserJet 6P to reveal the three memory slots.
Position a memory module so that the cutout in the module faces down. Slide the metal contacts on the bottom of the module into an empty memory slot at an angle. After inserting the contacts fully, tilt the module until it stands upright. The metal clips on the sides of the memory slot grip the module when it is installed properly. Repeat this process with each LaserJet 6P memory module that you want to install.
Replace the cover over the left side of the LaserJet 6P, and lower the top lid.
Replace the cables on the back of the LaserJet 6P, and turn the printer on.
Print a second test page to confirm that the LaserJet 6P recognizes the new memory.