Almost forgot, sure thing. I don't know the innards of the Q40. But, when you remove the bottom cover on the Q50. Near the bottom left (if the pitch controls are facing you), the cue arm mechanism is controlled by a piston-like device. When you press the arm to move up, it pushed the piston in, and when you release it just disengages and let the spring return it to rest.
*****If you are going to attempt to do it please remove: the headshell, counterweight and cue arm rest****** Let the tone arm rest gently and be careful when moving.
Back to the repair work: The space between the area of the piston to coat with the dampening fluid is quite small. I used a angled syringe (nice to have but a pain to work with, especially with such a high dampening weight) to get some of the area covered and try to get some inside the piston mechanism. Pressing the cue button to "smooth" out the fluid a few times, coat some more until you are satisfied. A Q-tip is nice if you need to remove excess or apply a large amount. But, take your time with it.
Hopefully that helps. However, I cannot guarantee this is how Sanyo did theirs, so I cannot claim for any damaged that may occur.