Instrument panel dimmer cancel switch peskiness

I use the "hold the dashboard brightness to cancel the dimmer" function on the Insight fairly often (I turn the headlights on in a lot of situations where it is still bright enough outside that I want the dashboard display to be at full brightness), and lately it's been getting extremely difficult to activate (often I have to try holding it in five or more times to activate it). Is this a switch that's easy to replace by myself? Should I take it to the dealer? I don't really like the idea of dismantling the entire dashboard to get at this part, but I will if necessary.

Thanks!