Okay cool. I hadn't seem those target sights before. Just googled them, really nice.
I really really hope that sight tool I bought will be able to adjust my front sight. If it can't, I don't know what else to do.
Only advice I can give you is more times than not a stubborn part doesn't need "heavy" blows.
You need a secure way to hold the rifle from moving or the muzzle up against a hard derlin block , very hard wood oak and or a lead block. Then a smart square hit should get it loose. The sight pusher will make small movements easier when trying to zero.