The suggestions I gave were in order of decreasing quality. Option #3 was intended to appear impractical enough that option #1 would seem more appealing. It's not impossible or terribly difficult; it's just going to require more work and the results are almost guaranteed to be worse.
Say I have the saved plot
A = imread('badplot.png');
plot(s(2)/2,s(1)/2,':o');
hl.Position(1:2) = [0.65 0.80];
print(gcf,'fixedplot3.png','-dpng');
Image displays are for visualization purposes only. They are presented using nearest-neighbor interpolation. Trying to take screenshots of images as an image processing workflow is unnecessarily destructive unless an unwarranted amount of care is taken. Don't be surprised if your image looks worse after creating what amounts to a screenshot of a screenshot.
Options 1 and 2 should be self-explanatory. Even if option 1 isn't acceptable (e.g. due to loss of data, etc), then option 2 should only take a few minutes. It only took me 47 seconds to use GIMP to copy and paste the legend into the original plot image:
