2000 firebird drivers side side skirt ground effects coming off

[rifsm1]

My drivers side ground effects is pukking off the body, I have never had to take them off or put them on and was wondering if anyone here could give me any instructions on how to fix it? IS it easy to do or should I take it somewhere and pay to have it done?

[ConElite]

My cars Pass. side skirt was comin loose by the rear tire. I kinda lifted and pushed it against the car really hard and it seemed to seat in and that was it. I dont know what i did but it helped. It was like 1/4 gap. Now its perfect.