Button on shifter sticking

How do you solve this problem? If you spray a lubricant, like wd40, silicone or graphite do you have to take it apart or can you spray through the space around the button.
Thanks in advance.

I thought I had this problem until I found out that you have to have your foot on the brake pedal before the button works. I don't suppose this is the problem, but you have to try the easy ones first !

Inside the handle of the shifter is a plastic piece that activates the shifter mech, generally heat can cause this to crack and cause problems when you push in the knob. I had to gut and replace the parts inside the shifter, WD only made the problem worse. This is what happened to mine, not sure if this is your problem but when we took the shifter apart, all the plastic pieces inside the shifter fell apart. Cheap plastic is heat sensitive.