Giannoni Diaphragm

I have a Sime Friendly with a DHW fault.
The DHW has to be fully turned on to make the diverter valve microswitch. I have been advised that the diaphragm only needs replacing not the whole valve.
I can get a diaphragm kit for £14 but before I take the plunge is there anything I need to know, or is it simply:-
1.switch the boiler off,
2.turn off the DHW isolation valve
3.open hot water tap (to drain)
4.remove 8 screws from top cover and remove diaphragm.
5.refit diaphragm and cover
6.refill and start up.
Any comments gladly appreciated......

yep! good luck!

OK will give it a go this weekend. (will have the towels ready)
Does my running order seem Ok then ?

yeah, just becarefull when removing the 'top cover' it holds down a spring underneath, thats what the pressure will be from when unscrewing.

are you able to remove all the screws with the valve in-place. thought these were a bit tight from (bad) memory?

Its a pretty unfriendly boiler!

Its possible to do it in situ but you need a good range of 1/4" bit accessories.

Tony