Reusing plastic pipe

[Serval]

I need to replace a shower valve that has plastic pipe going into the compression elbows on the back of the unit.
The photo shows one of the said pipes in the background

Having not worked with this type of pipe before can someone let me know the best practice when connecting everything to the new unit?

Should the pipe be trimmed back clean and fitted with a new olive to get the best possible seal or can it be reused as is?

 

[ShaunCorbs]

Yes you can but leak test before you close the wall up