Water/Heater switches

Hi,

Second attempt at posting this!

Does anyone know how to remove the modules from a Power Modular System PMS7GL console, please? I had to replace the 'O' rings and diaphragm on the Whale water pump connection a few days ago, after which everything was working as it should. I also had to replace the drain plug on the Cascade 2 water heater (see my post in Introductions), but did not turn the heater on as the van was not connected to mains power. Before leaving the van I turned off the water pump switch. 

I have just been out to do a follow-up check and am pleased to say that there are no more leaks. However, I cannot test it under pressure as the water pump switch on the console is stuck fast in the off position. My son is an electrical engineer and I will ask him to have a look at the switch, but I can't see how to remove the module from the console: I have got as far as removing the surrounding fascia, but that's all. The intention is to identify any fault and repair or replace as necessary. 

I'd be really grateful for any advice or information as we are hoping to go away for a weekend before the end of the month.

Thanks.