I have replaced mine a few times............................due to having the side sills repainted
.............more than once.
Not a big deal to just eyeball them. You only have one chance to get it right though.
Just remember, they are parallel to the body lines on the car, not the ground your parked on.
As long as you don't put them on upside down, almost impossible to screw up.
There is a sloppy fat guy named Bubba at CAAP that puts on the original badges. If he can do it while eating Doritos and donuts, you can manage to do it as well.