You can remove the sight base by carefully tapping out the basepins from the small end to the large end of the pin (if if different sizes).  Then you're left with two holes to fill or you have a thin section of material between the bore and the hole.  You can re-insert the pins and dress them down carefully.  We'd recommend a gunsmith.

Then you can put on another device.

This pin problem is the reason we went with clamping devices.  Easy to work with, zero, etc.