I think a couple folks are missing the details. The OP says he has a 1903"A3" with a 1903 barrel. Those two models have completely different front sights so if the barrel is actually 1903 then the answer is easy. The 1903 had a dovetailed blade base that had a set screw in the front (muzzle end) simply remove the screw and tap the blade and blade base assy out of the base assembly.