Both of these ways seemed a bit barbaric and unclean to me, so I just left the two controllers be figured they would have the screw mounts if they needed the brackets, but they don't.
Another person reported superglueing the heat sink directly to the controller. I've read that one guy butchered his old board and superglued the screw mounts onto the new board. The only other difference is that the new boards do not have the small heat sinks over the USB controller and one other controller (not sure what they are). The display cable was a tight fit, but working carefully and with a gentle yet firm hand, I was able to fit it into the logic board port. I purchased a mid 2012 non-retina logic board (without the heat sink → reused my original one) and installed it successfully, upgrading my USB ports, Thunderbolt port, CPU, and GPU. I have an early 2011 model 15" MBP with a matte screen.
What gives me the right to say I know? Well, I just did it last week!