How do you replace the red door that covers the filter bin?

After two months, the latch cracked on the 960 dust filter door. Given the 12 month warranty period, they are sending me a new replacement part. Hope it lasts much longer. Apparently a new door costs in the order of $25.

I know I’m responding to somewhat of an aged post but I just experienced the same issue and received a free replacement door from iRobot. I remove the four screws from the top of the bin which holds down the cover which the filter door is attached to. There are is a scissors type spring attachment that attaches to the cover, the two posts holding this one can simply push through giving you easy access to the underside to add pressure to the cover arms for removal. Assemble the bin cover in reverse order.

The even simpler way without removing the bin cover is to simply break the arms off from the red filter door letting them fall through in to the dust bin then attach the red door by pushing the new door arms through the slots.

Where can I order just the door?

On Roomba model 985, there are 5 screws but only 3 are visible. I have marked the remaining 2 in red on the attached picture. The two screws are under a sticker. I did not peal off the sticker but just poked through it with a phillips screwdriver.
Once you unscrew these two as well, the assembly lifts off. The scissor like mechanizm can be disconnected by pushing the scissor parts out of the holes they are in.
Lastly, the red trap door, it also removes by compressing little knobs on the hinges, if you break it, do not fret, the latch of the door is broken already, as this is why you are reading this post, right? :)

Have fun!

We've had our unit for several years and have replaced the door during the warranty period and thereafter continued to have periodic issues with the plastic catch opening. Finally we contacted CS and was told since beyond warranty period would suggest purchasing entire waste assembly. Pricy solution but did so in January and again we're experiencing same issue. Will advise after I have yet again another conversation with Roomba CS today.