What type of roller is this?
Thanks for writing in! The roller you have here appears to be an older version of the 84-016 Screen Door Roller. Unfortunately, I am not confident your exact style is made any longer. Is this roller similar to the one you purchased?
Since the shape of the connection piece differs, it is likely you'll also need to replace the screen corner. You will find this piece installed in the door framing. The corner compatible with the 84-016 is the 95-020 Acorn Patio Screen Corner.
Be sure to take a look at the two video tutorials tagged below this thread. They provide detailed explanations for removing screen corners and rollers.