I have a G26 I'm trying to install a set of trijicon HD on. I have the factory glock sight pusher but it isn't working out. The rear will barely slide in the dovetail at all by hand and gets extremely hard with the pusher before it even gets halfway. I tried barely taking a file to one side of the dovetail on the sight hoping to make it fit better but Im afraid of taking too much. This is my first go at installing sights and I'm not sure what I'm doing wrong. Any help would be appreciated.