midi controller knobs problem
 

hi...i have an evolution midi controller...its 5 years old...
well some of the knobs on it are a little screwed up...when i touch them or turn them,the knob keeps changing values on the screen...like a loose connection or something....
for example...if i turn it a quarter turn and then let go of the knob, the numbers on the screen keep fluctuating...this means that whatever parameter it is linked to keeps fluctuating...

i think this is being caused by dust that has accumulated inside/under the knobs.
Is there any way i can clean the knobs...like open up the keyboard and use some sort of cleaning liquid or something like that?
or should i not mess around with it and give it to a pro to service it ??

have any of you had this sort of problem?