Another Tail Light Question

I want to remove my brake lights to change them.... Once i unscrew the 2 screws on the lenses, shouldn't they just pull out, or am I missing something, I undo the screws but they seem real tight, like something is holding them in near the side of the car, around where the turn signals are. Again, Thank you.

ususally there are three bolts holding them in, but some companies use a thick black glue to hold them in..and you just have to pull to get them out..i know that nissan does.