How to replace Neff dishwasher pump cover?

I have removed the white dishwasher pump cover on my Neff (it wasn't draining and I got a piece of old, stiff clingfilm out which may have been the problem) but now I don't know how to get the pump cover back in. I know if you hold it in the right place you have to push down and it will click back in, but how do I find the right place to position it and which way up should I be holding it before I push down? The dishwasher model is S41E50W0GB