I've done a number of Marlin triggers, and it's fairly straight-forward. Some things that will help: Pry up on the trigger return spring - not too much or you will have to remove it & bend it back down. You can also remove a couple coils from the hammer spring. Again, go slowly. I think Wolf makes the proper spring with a lesser tension, but this will work for less$.
You can CAREFULLY stone the engagement surfaces of the hammer & trigger. You don't want to try to change the geometry as much as you want to smooth it & remove burrs.
If you're not completely comfortable with this, a trigger lightening job is usually not that expensive. SW