I am having a tough time putting the filter holder of a la cimbali m21 back up. I applied a bit of grease to it, but no avail. Is there a tool or something that I need to get (I have been able to just push this in with my hand in the past - maybe I am just getting old and have gotten weaker)

I had to remove the filter holder because I have change the gasket.

So I finally solved this problem by getting a giant clamp from harbor freight and creating a small wooden jig.