Fisher & Paykel Dishdrawer help – how do I clean the pipes?

I have a Fisher & Paykel DD603 double dishdrawer. After 5years one of the impellers (aka motors) got very noisy so I have ordered a new one. It was a little mangled and I think some fragments of glass and china have got into the system over the past month as I have had 4/5 chipped mugs and glasses. I would like to clean out the pipes to remove these chips, otherwise they will just damage my new impeller/motor.

I managed to remove the drawer from its runners, but stopped going any further because I realised I dont know where to go from there.

If anyone can guide me through how I clean out these pipes, that would be fantastic. Thanks for any help, Josh

PS – does anyone else find the design of the oval/egg shaped filter thing in the base of the drawer ridiculous? The mesh doesnt cover the drain hole, so it lets chips etc straight through! Bonkers.