The 540X triggers were already pretty good...three-way adjustable.
They look a lot like the Remmy 40X as well...might be worth checking to see if they parts-cross.
Check the 541 as well...
A lot of Remmy triggers interchange, but I've not found a listing of what does & what doesn't yet.
You have three options...
1. Call Remington and say you have a trigger issue, then pay them to put in a new trigger, as you are WAY out of warranty.
2. Have a gunsmith do a trigger job on it, as that's the SAFE way as well.
3. DIY, but be aware that if you mess up, dangerous things can occur.
If you decide to do it on yer own...the three screws are...
So probably all you need is a good cleaning on the trigger, sear, and anyplace the trigger or sear also touches, like the posts they're mounted on.
Don't change anything, just clean it and get the rust off. That usually gives you a MUCH lighter feel. Then oil & reassemble.
That's the most anyone without a gunsmithing license should
do. Legally speaking.
Test it after reassembly, make sure the pull isn't too light, adjust the things that you're allowed to adjust, and make sure its safe.
Then, if safe & functioning properly with dummy rounds, take it to the range and test some more for happyness
Then if that's not enough, read this. Remington Trigger Adjustments
Most of the old guns I've worked on, simply needed a serious detail cleaning...
and its amazing how much better they act after you do it.
Most of the time, that's all you need to do...Field Strip and Clean meticulously.