If you are refering to the mtech bumper lip, from the factory it comes glued on with this insane glue. You can buy it from the dealer and its expensive.
It you use 3M tape its very tricky to put on the lip. Its kind of a one time shot thing.
Definitely a two person job. And yes it will raise it up especially when looking from the side where it meets the bumper right in front of the wheel.
Personally i used the 3M tape, it holds up pretty good. Glue would have been better tho
If you use the dealer glue you get a bit of time to adjsut and align all the spots and everything will be flush. One downside with the glue is you will never ever be able to take the lip off.