when i put mine on i was worried about the bumper too. i just took my wheel off to see what i was doing, pulled back the plastic and installed the driver's side. for the passenger side i didn't even take the wheel off. took me about 20 minutes including taking the driver's side wheel off and putting it back on.
these are exactly what I was gunna post up... pictures and all
(everything except the wheel removal)
plastic is plastic... you bend it one way. when you are done, just bend it back again