Heater Matrix

[IPBR21054]

Hello can someone advise how long it will take to replace the heater matix and if the dsash needs to come out or not.
The reason i ask is because the inlet and outlet hose that connects to the plastic pipes that pass through the bulhkead one of them is snapped and then the two hoses have been joined together.I have no heating and noticed this when i looked under the bonnet.
Can this plastic pipe be replaced or do i need a complete matrix with these pipes atteched ?

Bmw 318 E36 1997 p reg
4 cylinder with manual transmission.

Thanks