Do you have your old control head with outlets and screw connectors? if you do (if the new one will accept the old one) then there's no need to disconnect everything first (I checked with my Autotrol dealer and they will let you do that without even charging you). Connect the old control head to the new one. If you have an easy way to handle a hammer or screwdriver I suggest you do it this way. If not, then do one screw at a time disconnecting prior to each :)
Hard to tell if it is a water heater from those pictures. A Serial Number of a Water heater should be on the side of the water heater. If it has a serial number there should be something written on it and I have found that every manufacturer has their own numbering for waterheaters.
1) remove the old controller head. 2) assemble the new controller head. 3) Reconnect or wire in the valves. I did the recon without the valves for easier access. 4) Just plug it in and test it. 5) Remove the old control head. 6) Refer to step 1 again to unplug the connectors.
Stuck in the new wall membrane with some style, permanently mounting it there is impossible, it needs to be unscrewed and then connected to the new wall (whick it'll do). 24x24=576mm x 600mm =29,6 cubic centimeters. d2c66b5586