Welcome to the forum its a great place to get your questions answered. You din't mention what rig you have. I have reattached the trim around the slide box using a pin nailer on several rigs with good results. I did find it works best by angling the gun at about a 30* angle.
Jake my sidekick (yellow Lab)
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho