I recently took my browning A-bolt medallion down to a little gunsmith near Indiana pa for the same thing. Not entirely sure what he did to it but WOW. He took the trigger down to 2LB and it breaks very crisp and clean. would highly reccomend him to you. Gresock Gunworks, (724) 349-1152
You can do the job yourself for about $10.00. Look up erniethegunsmith.com on ebay and order a varmit spring. It is very easy to install yourself, and it will bring your trigger pull down to 2 lbs. It will also be crisp.
You can also take the spring out and file or grind a little off an end and reinstall. I do this with my A-bolts....no problems, easy, fast and works. Make sure you have the screw adjusted for the lightest setting to start then a take off a little bit at a time. You can increase with the screw if you need/want to. My A-bolt triggers are somewhere handy to 2lbs and crisp as can be.
As the proud owner of two A-bolt stailess stalkers I would only ask one question, why would you change it..you can adjust it for pull and travel, it's pretty smooth and only needs to be turned down a little..anything below 3 pounds in a hunting rifle would cause you to be a little careful with gloves on.. a little filing on the sping could lower it a little but I can't see the need..mine are fine from the factory and I've never even thought about anything ligher in a hunting rifle.
It's been more than ten years, but adjusting the trigger myself on an A-Bolt, with a then new bought small screwdriver, adjusted the trigger, enough for me. I thought the low adjustment was good enough. The small group certainly wasn't hurt.
Give it a try. I think they're set from the factory at the hardest pull. All the A-bolts I've ever owned came with pretty dang crisp triggers to start with. My 257 doesn't even seem to move then breaks. My 300 had a tiny bit of creep to it, but it was still leaps and bounds better than any other factory trigger I've shot. Had a Win M70 that had a creepy, heavy trigger....easy enough to adjust though and I tinkered with it until it was light and crisp(not too much though!). Great shooter after that....actually one of, if not the, most accurate rifles I've ever owned. Sold it though because it weighed a ton and wasn't very handy for still hunting being so long and heavy.