The motor will bolt right in.
The stock pinion gear however will not fit on the vxl motor. Stock motor has a 5mm shaft, vxl motor has a 3mm shaft.
Other than needing a new pinion gear, its an easy install.

How old is your stock motor? It may still be under warrenty. Even if its past the 90day warrenty, redcat also has a replacement program that could get you a stock motor at less than retail cost.