I used the Rough Country winch plate with D rings:

 

Essentially you need to do both from my understanding. The stock bumper is not strong enough to mount a winch on it by itself. There has to be a winch plate. The winch plate mounts onto the front frame rails, and then the winch onto the plate.

When I looked at modifying the stock bumper, it just seemed like too much work for what it was worth. I rather go out and get a cheap china bumper than fool around a compromised solution anyhow. Fortunately for myself, someone had an AEV front bumper on CL for $250, so it became a best of both worlds solution for me. Those options are sometimes out there as well. It just takes some patience and some shopping.