Getting the stock front bumper off seemed kind of tricky, but the replacement DE unit mounts the same. It gets pinched between the chassis and bulkhead when you tighten the screws.
Here is the post with the photos of the skids mounted.
http://www.rctech.net/forum/7060455-post1003.html
Here is the one with the photos of the street tires.
http://www.rctech.net/forum/7060460-post1004.html
ben