Hi,
Here is a link to the Ifixit guide on how to replace the motherboard in an Asus Chromebook C201. This is handy as by using this you should be able to gain access to the DC-in socket in the Chromebook.
[guide|60770]
Unfortunately the only replacement part that I can find is for an ''Asus Chromebook C200MA'' [http://www.laptopinventory.com/ModelDetail.php/Asus/Chromebook/C200MA/DC%20Jack/35241|here] which is identical to the DC-in socket for an'' Asus Chromebook C300 ''[http://www.laptopinventory.com/ModelDetail.php/Asus/Chromebook/C300/DC%20Jack/35275|here] which is the same as a DC-in socket for an '''''Acer''' Chromebook C201 ''[http://www.laptopinventory.com/ModelDetail.php/Acer/Chromebook%20/C201/DC%20Jack/53494|here] so I suspect that all Chromebook DC-in sockets are the same.
You may wish to inquire with the seller whether this is the case or not. (these links are not a recommendation to use the seller only to show what the part looks like)
Hopefully this is of some help.