1) clean & deburr all parts so they move freely
2) determine if all spring are original ,  or at least not 
    overweight replacements
    if you don't know what to look for post good pics 
    top and side view   
3) purchase replacements or grind to lighten if needed
4) a too heavy coil main spring will cause a heavy trigger pull
    even if all else is perfect ... I assume a flat main spring 
    will cause the same problem but I replace flat mainsprings
    as my very first step no matter what else I'm doing.
5) altering hammer notches and sear noses is best left to
    a very capable professional 

1885s are known for having great single triggers

Here's a place to start.  Bottom of the page.

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