air intake coupling rubber to plastic problem PLEASE HELP
 

When changing the MAF on my 1999 clk320 the rubber intake hose behind the maf got disconnected from the plastic intake housing behind it. They are connected by a round coupling which appears to have little friction tabs to hold it in place.

I have tried at length to put these pieces back together. The best I have done is get half of the pieces joined with the coupling the rest will not budge. Is there a trick to this. I asked a MB mechanic and he said to buy the pieces as a unit and replace. The pieces are made to disassemble. If I need to remove the rear plastic manifold, what needs to be disconnected?

Please offer any advice as the duct tape is offensive at best to look at.


Will someone please help, I am lost on this.