Well, installing RAM in the primary module is even easier.
Simply flip over your laptop, and remove all the screws from the service panel (after removing the battery first), then open the panel.
The primary RAM module is right in the middle of the mainboard, just gently pull the securing prongs away from it and you can pull it out. Inserting the new module is exactly the same method as the one shown in the PDF file earlier in this thread; insert the module at an angle, then press down and it will click into place.
Then simply screw the panel back into place, put the battery back in, and that's it.