Baxi 105e pump head removal plumbing advice

Baxi 105e pump head removal Hope you confirm something’s for me, boiler calls for how and ch but am not sure if pump is rotating, have checked if it’s stuck via inspection cap on pump which is ok. 240v at pump and on pcb so that’s ok. Can someone tell me how I check if it’s rotating, if not it states drain primary circuit I presume this means shut all valves on cold inlet, supply and return on ch and drain system via drain clock, or am I missing something like drain whole system completely. Many thanks in advance

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