I changed mine out myself. First time for me. It went pretty smooth, actually.
I installed the Ameriglo pro i-dot sights. I love them. Easy and fast sight acquisition.
My friend rbMPSH12 had AllenM swap sights in his for some night sights and loves them. (Ameriglo, I think)
I think the Big dots are an acquired taste, and most users (after practice) love them. I personally don't know if I'd like them all that much.
E mail headed your way with info you are looking for. Good luck