WARNING, NOT MY PROFESSIONAL ADVICE, NOT STI'S, AND NOT SHOOTERS CONNECTION'S!
That said, when it happened to one of my STI's, a contact in customer service at STI told me to take my brass hammer and strike each front corner of the sight body enough to bend in the corners near the pin. It worked, and didn't damage the gun or the sight. He had said I could send it to him, but this was a much easier fix.
USE A BRASS HAMMER, DO NOT BEAT IT WITH A 10LB SLEDGE.