Tips for loosening extremely tight straps on a winch?

An option could be to test how tight the straps have been winched down before doing any work on the trailer.
If they are so tight that you can not reasonably and safely release them, then go over to the people who are doing the loading and over tightening the straps, have them back them off a tooth or two. Would try to find the supervisor of these people, have that person try and get the winch open. Bet that would get some traction.

 

Can you do a video of that for us?

 

Why, do you weigh 110 pounds to?
I haven't a clue how to post a video.
Here, even simpler
Get yourself a 1" ratchet strap with hooks on the end. Hook the hooks into binder end of winch bar and adjust the strap to correct length. Now put your foot in it.

 

LOL...no thanks. You go right ahead though.

 

Why would I do it?
Heck I'm to lazy to tighten mine.

 

So thats how you get your straps loose! Never tighten them!

 

Tight is good...but over tightening is not good. I have a driver who wouldn't be 110 lbs in steel toe boot, and wearing 17 coats, and holding a thermos of coffee. But she does just fine, and gets loads as tight as needed. She is as agile as a monkey climbing on and over or under things, so in many ways her petite size is an advantage. While i rode with my new lady as she is getting used to bedding heavy equipment, my petite driver followed us with a wheel loader on her trucks bed. She loaded herself and chained it down with no help, as she does all the time. She follows my simple rule of when its chained down well, add a few more chains. They are always plenty tight. Nobody should be trying to rip the attachment points off the trailer, just snug tight. But myself and my drivers that work for me also do up our own binders, nobody does it for us, so we control that.