changing a head gasket is fairly simple on the 4.0 in comparison to other engines i've worked on. the only thing i would be concerned with is that it is a blown head gasket and not something else. tips in general that i'd say if you do this on any vehicle are to have head checked for flatness, try to remove as much coolant from head/ block before its removed, and make sure that the head bolt threads are clean as well as the threading in the block to get the most accurate torquing, and lastly torque head bolts in the correct order (just check a manual) hope this helps you out