Good result, glad to help.
For other victims, the strap sits between a couple of guides, but if you wiggle it out from between them (like I did last week) the angle is such that you can't then pull hard enough to release the catch. The strap has a sort of arrow head with a hole in it. The technique, I have found, is to spear the hole with a stiff metal skewer and then push downwards using the skewer as a cantilever. It could have been engineered so much better, particularly for those with limited dexterity. And, of course, it is right down at floor level, so both difficult to get at and to see.
The drain cover has a cunning hinge which means you can remove and replace it completely without tools. This makes it much easier to drain the drum, using the little hose, or to take the pump cover off without getting water everywhere. But again, this is not intuitively obvious.
Oh, and the one essential tool for these jobs is a wet and dry vacuum cleaner, which lets you catch all the leakage without getting puddles all over the floor.