At least a couple gunsmiths offer it, so it is possible. The main problem is the interface between the sear and the striker is critical, changing the angle and amount of engagement smooths and lightens the trigger pull, but if you do it wrong you get an unsafe and unreliable gun.
With an unloaded cocked pistol, leave the topcover off, hold the bolt in place, and watch the striker as you pull the trigger. If it moves rearward that is a major source of your heavy trigger pull. The angle of the sear/striker engagement surfaces can be changed so the sear moving downward no longer cams the striker back. Get the wrong angle and there will be ......trouble. Beyond that it should be like any other trigger work, just polish and smooth every contact point between the trigger/sear/striker for smoothness. If the trigger return spring is really stiff it can be bent to releave some pressure.