Repair Plane Plastic or Replace?

[netsurfr]

The vent duct in my Dakota has a couple of cracks and I would like to fix it (or replace if that's better). My question is how does that vent cover get removed (other than the screws holding it in place)? The vent open/close knob is wider than the small hole for the cable so there must be a way to either remove the knob or disconnect the cable to slide the vent cover in/out? My plan was to remove the vent cover and patch up the cracks but I've heard these plastic pieces are very brittle so want to avoid making the problem worse by experimenting how to get the vent cover removed.

This is the part in question...

 

[BGFYankee]

 

[raymos]

 

[netsurfr]

 

[netsurfr]

 

[raymos]

 

[voretaq7]

 

[netsurfr]

 

[netsurfr]

 

[raymos]