Primer button replacement on a Briggs & Stratton?

My primer button on my Murray push mower went bad. I have purchased a new primer button, but I would not figure out how to fix it this weekend. I took the carborator off but could not see how to get the new primer button in. There where 4 screws holding the whole fuel intake part, but it looked like the plastic that the primer button fit in should come off but I could not get it off.