Here is a view of the assembly with the screws removed.

Insert some sort of prying tool between the tail light assembly and the body, just below the crease in the body and pry to the rear of the vehicle. a snap will be felt/heard as the plastic stud releases

Move the prying tool to above 1 1/2 inch above the bottom of the assembly. Insert it between the assembly and body and gently pry toward the rear of the vehicle. This should free the second stud.