From the TAZ Workhorse Manual:
"If dust is evident on the control box vents, unplug the printer and use short bursts of compressed air to blow out any dust. Once a quarter it is recommended to completely open the electronics cover, and blow away any debris on the board using short bursts from a can of compressed air."
Do not open the electronics enclosure when powered, as there may be high voltage present. Make sure the USB and power cable are both unplugged before opening the enclosure as well.
The picture above shows the location of the fasteners that will need to be removed in order to access the electronics on the TAZ Workhorse.
Step 4 of
this guide shows how to remove the cover for the Mini / Mini 2 printers.