Re: Miele heater.
I normally open up front of machine, then remove wires from heater & NTC. Pull out NTC (it just pulls out) then grip heater gasket with pump pliers through NTC hole & pull gasket & heater out in one. You get new gasket with heater. Fit new gasket on heater push in place (make sure gasket is lipped onto suds container). Then I refit shield, retaining washers, wiring & NTC.
Hope this helps its straight forward job. clayside