Fuel Filter

Hello all. How do I connect the fuel pump to the fuel filter?

I have a 2000 Corolla that sat for a while. The fuel pump needed cleaning so I disassembled the sending unit and cleaned it. When I removed the pump from the filter, there was a round black clip that I had to pull back from the filter with a flathead. When I removed the pump, this clip stayed with the pump. There was also an o-ring and a white plastic piece. I reassembled by having the filter, white plastic piece with smaller diameter surface up, oring, clip, fuel pump. It did not seem to go back together as it was before seperation. I was worried the fuel pump would pop out of the filter once I was driving it down the road, but thought that when I assembled the whole sending unit back together, it would hold it in. I was wrong. The fuel pump popped out of the filter.

I have spent many hours on the internet trying to find instructions on how to connect the fuel pump and filter. Schematics do not show the oring, black clip, and white piece so I do not know the correct order or orientation. All the instructions I have found basically say insert fuel pump into fuel filter, but do not explain how to do that. How do I do that? I can post pictures if needed. Thanks.