Nighthawk X8 Intermittent Internet & Wi-fi Disconnects

My Nighthawk X8 - R8500-100NAS router which I use as an access point, has been losing the wi-fi Internet connection every so often.  I solve the problem temporarily by turning the router off and on and it works fine for a few more hours.  The problem seems to be getting worse and it shuts down faster now.  I have updated the router to the latest firmware, but that did not change anything.

I think the problme might be heat related and I would like to take the router apart to clean it out.  Are there any instructions on how to take it apart?  All I see are two tiny recessed scews on the bottom.

Maybe it is just starting to fail and it is time to get a new router?