There really isn't a way to explain how to do it correctly over the internet that I can come up with.
Someone will chime in though.
Be CAREFUL when you test fire. If you screw this up you may have it fire when you drop the slide to load a round, and it might go full auto. If you are really unlucky it will go full auto when you drop the slide. These are the 'good' bad things that can happen, you can also wreck the sear in short order if it isn't clearing the half cock notch completely.
Spring tension can be used to put that last little touch on a trigger job, but it should not be used for drastic changes in trigger pull weight. That is what good fitting of the parts is for.