For safety reasons, I will not publish exactly how to do this, but it is incredibly simple.
Look at the connectors on the purge controller, they are all labeled.
The purge controller works by preventing the power supply from receiving line voltage which powers the main board in the robot. It does this by monitoring both pressure and flow. Ignore the monitoring inputs, you want to bypass them. Just realize what they are doing on an electrical level, and you should figure out how to bypass the controller very easily.
Hint, these are very useful (they also make undoing the bypass very simple if you need to use the robot in a hazardous location again: