Noisy Primary Set Top Box Fan - PX013ANM - getting louder

I have model PX013ANM set top box that is very noisy. Seems to be the fan from the other posts I have read.  The fan on my box is constantly running and at night is louder than the volume on my TV.  Are there any recommnedations for quieting the fan?  BTW, the box seems to be running hot and is on all the time.

Thank you,

Joe Z.