Air Con cooling unit

Hi guys,

I'm replacing the engine loom so I've removed the glovebox and need to remove the above part to get easy access to the loom retaining bracket on the bulkhead.

Looking at the service manual I need to undo 2 pipes that run into the back of the cooling unit, I'm assuming I will need to drain the system, where is the drain point on the car? I will be deleting the air con anyway so I'm assuming I won't have to put the pipes or the cooling unit back after the loom.