Its not hard, just subsitute this part for the 808 part, it bolts right in.
Xray part number 354011
http://www.amainhobbies.com/product_...ducts_id/13398
Just get this part and replace the one that comes with the 808 kit with it. The center dif mount plates that come with the 808 are a couple mm shorter than the RC-Monster Xray motor mount. The RC- Monster mount was designed to work with the old xray buggy and truggy parts but everything works on the new buggy except for this part.
Triming the mud guard where the motor mount hits it is easy. Dremel or hobby knife or even body scisors will do the job. Again.. its simple and obviuos when you see it.