Slip fit. If it's not working for you, you're doing something wrong. Unfortunately neither of them shows the actual entire fitting, but they both indicate the same thing, and goes in just like Ljugtomten says.
Managed to fit the antenna from the top of the holder after threading the connectors in. The connectors only fit on the edge of the hole. I just wish they had included some instructions in the manual on how to do it.
