Air guide (duct) replacement
 

I was told that rodent eaten the air duct from the ventilation to the rear part of the cabin. So, I opened the center console cover to look at, and it appears that indeed something has eaten the air guide. Here's the pic.
https://goo.gl/photos/6Nb5c8x12aDxM3iA6

On the picture I circled the part that has been eaten. I believe it's called "air duct", P/N 955 573 316 00 in the catalog. I want to replace it but have a couple of issues.

The first issue is that it seems that the rats also eaten the insulation foam, which is shown with an arrow on my picture. It's better seen on the next picture. Can someone tell me what's the part number of this foam?

http://www.pelicanparts.com/techarti...mall/pic03.jpg

The second issue is I'm not sure how to replace the damaged duct. Can someone point me to the instructions or do-iy-yourself guides?

Thanks