ISE10 1606W door lock

Having been at the point of almost throwing out my ISE10 because the drum was no longer turning it appears to have come back to life after I turned off the water to the house (for an unrelated reason) and then turned it back on. The only thing it is not doing is unlocking the door at the end of any programme. It also seems to be much harder to shut the door than it used to be. The only way to open the door is via the pull-cord. Is the door lock serviceable in any way (lubrication?), if not how easy is it to replace? I can see the part is available, but these generic instructions for replacing it don’t look like they would apply to the ISE10. Is it a straightforward job? Any advice gratefully received!

Thanks
Peter