Smaller heat gun nozzle might help. Adjust the temp to be around 270C, or if it's cannot be adjust, the solder should be melted first before the board burns.
Lifted pad can be cause by excessive force when you pull the component while the solder hasn't melt completely, or the PCB quality is very very terrible so the heat can destroy the pad.
Protect other surrounding component with aluminum foil. Or in some other super difficult case, place damp tissue paper on top of the IC next to the component that you want to remove and than place aluminum foil...after that, use heat gun and wala! the other components temp is lower so it would not melt.