VP9 Sight Adjustment

Don't know if this is the right forum to ask it, so move if necessary.

I recently acquired a VP9 from a forum member here, Heinie straight 8's on the gun. It shoots significantly right, and the rear sight is significantly right of center in the dove tail. I cannot for the life of me get the screws loosened to adjust and the interwebs tells me nothing.

What am I missing?

Have you tried heat?

Soldering gun with a long tip that can reach inside the hole for the screws. Apply heat in 5 second intervals and gently apply torque.

Looks like I need to find me a soldering iron.