How do I remove my novak sights? (1911)

[diowk]

I have a springfield trp 1911a1. Im trying to change the rear sight but even with the little alen screw out, I cant get the sights off. Im not too concerned about damaging the sights since they already are ( thats why Im changing them ) but even sharp blows with a punch and mallet, the sights wont budge. Its like they are totally fixed to the frame. Any ideas?

 

[Any .45]

Well I had this happen on my Loaded model, turns out there was some loctite, used to lock the sight in due to SA sending out some loaded model with loose rear sights, the screw came out perfectly fine but the sight would not budge. What I ended up doing since the sight was done for on my end. I ended up using a small butane torch and heating it up for a few minutes then just gave it a few nice hard taps and sight came out perfectly fine and no damage to the gun or even the sight. Just remember not to be over generous with the heat.