Clean it and lube it first.
I would suggest not working on the trigger yourself because it is a semi-automatic with the risk of full auto. Timney has offered trigger assemblies in the past and may yet for all I know.
I'd suggest a smith who maybe does trigger work on 1100's and such. The sear/hammer relationship is usually shipped with enough of a hook that the trigger first cams the hammer backwards against the spring before releasing the hammer to fly forward. Setting the angles carefully and smoothing everything up will produce a fine light trigger - getting the angles wrong will produce an illegal full auto. Mine was done by the smith at Marshall Field's in Chicago many years ago when Field's still had an extensive gun department on the top floor that was real competition to V.L. & A. along with marble paneled restrooms. The marble was repeatedly vandalized and we all know what happened to gun departments in Chicago. I told Phil I'd pay him to do whatever seemed good to him after I bought the rifle and the trigger was great the accuracy just fine given the rifle didn't fit sandbags well and I used a K3 Weaver - in no way inferior to bolt guns. Tom Hayes wrote a number of gun and hunting books in which he praised the 742 but also suggested derattling the magazines which I did find necessary.
Gas gun loads - medium bullet weights and medium powders as suggestted for the Garand are definitely best - bolt gun loads with 200 grain Nosler round nose and a lot of H205 were definitely too high pressure at the gas port with cases still gripping the chamber walls and resulted in seriously bent rims. My understanding is that the Remington extractor with just right heat treat works beautifully but sometimes the heat treat wasn't perfect and the extractor will fail and replacements are hard to find.