frustrated and becoming broke

hey everyone, this is curly. I am trying to install a set of hi-viz sites on a friends gun. my site pusher does not let the slide sit in the correct position to push out front site. I used(and chewed up) brass punches.no success. I even used arkasas stones to try to shave a minimal amount off the sight to make it esier to punch in. no success. I even ruined one front site and had to replace it for him. HELP!!!!!!!!!!!