OK. Had a look but nothing obvious. I could take the pipes off but may cause more damage. To be honest I don't thing I will bother fixing it as it isnt too bad. No signs of fluid and it seems you need a special tool to get the top ring off? If it was a simple fix I would do it.
It is certainly a job you can undertake yourself..just be careful when disconnecting the hoses from the nozzle and avoid excessive force. As Edinburgh mentioned, they can be brittle.
If you are struggling to release the locking ring by hand as mentioned by Rob40, then you could use a large flat bladed screwdriver and hammer to ‘chisel’ the ring loose. Wrap the tip of the screwdriver with a piece of cloth to avoid knicking the plastic ring.