Temp sender help

[Rmachines]

Hi i posted this before but put it in the wrong place

I have a TIM Water temp gauge but i dont see how to fit the thing?

Its got a small brass sender unit and some adapters, but the sender on my engine is plastic which pushes and clips in. Also i need to keep my OEM one connected. Has any one here every fitted an after market gauge? Any ideas please share

Cheers.