I need help with a map

I'm trying to get it so that one square on this map that I downloaded is the same as one square on the grid, but it's really difficult. Below is the map that I want to get working. It's admittedly a bit large, but there should be a way to get it to work somehow, regardless of the size.

Have you "discovered" the very exhaustive sticky thread that  that explains this kind of thing (and is currently listed just above your thread)? ;-)

I have used that map in my game (albeit with some personal tweaking to add an underground docking area... my players have even claimed this as the basis of the stronghold... but that is by-the-by). The suggestion of Simon is by far and away the best advice you will get, otherwise be patient, resize it manually pixel by pixel and use alt-drag to move it around until it fits (or you are happy with the fit). I found that zooming in on a smaller section was easier to get lined up, then pan to the far side and see how far out you were... you'll get a feel for how much bigger or smaller each square needs to be to get it spot on in time.

one problem that you may be having is that the image itself (most i get from pdfs) are out of scale and need to be shrunk/lengthened with photoshop or GIMP

Personally I just find it easier to remove the roll20 grid and turn off snap to grid.

meep