You will also need a breakout board in order to download the code to the router when using Actiontec's instructions. Amazon has one available fairly cheap here. The following is the search result for this board and a few alternatives:
Support for Cavium Octeon processor was added by change id 15640, thanks to David Daney from Cavium for adding this support.
Actiontec MI424-WR Router and Related Items
If you broke your MI424-WR and there is no way to fix it you can find a new or used online. I did find a bunch of stuff when searching Amazon for the router (#ad), but watch out since there are different revisions of this router out there. To get the right one, make sure to read the details and the specifications of the router. If it is a marketplace iten, check with the seller to make sure they are not selling an older version which has the slower single core processor with no 802.11n radio.