在更新时重新声明一个类

I am having a small problem when it comes to redeclaring a class. I made an update function that calls to a remote server, gets the files/classes, and updates it on the current server. The problem is I have to use a class the has been declared already because the new class contains features that have been updated.

I've been trying to unset the class but that does not work and I don't see a way of removing the require_once() of the file and then re including.

So is there a way where I can redeclare a class and have it run locally and not on the global scope?

You can use the runkit extension: runkit-import