Well, assuming you can target it with jQuery it should be just as simple as calling remove() on the element:

$('link[rel=stylesheet]').remove();

That will remove all external stylesheets on the page. If you know part of the url then you can remove just the one you're looking for:

$('link[rel=stylesheet][href~="foo.com"]').remove();

And in Javascript

this is an example of remove all with query selector and foreach array

Array.prototype.forEach.call(document.querySelectorAll('link[rel=stylesheet]'), function(element){
      try{
        element.parentNode.removeChild(element);
      }catch(err){}
    });

//or this is similar
var elements = document.querySelectorAll('link[rel=stylesheet]');
for(var i=0;i<elements.length;i++){
    elements[i].parentNode.removeChild(elements[i]);
}

If you know the ID of the stylesheet, use the following. Any other method of getting the stylesheet works as well, of course. This is straight DOM and doesn't require using any libraries.

var sheet = document.getElementById(styleSheetId);
sheet.disabled = true;
sheet.parentNode.removeChild(sheet);

I found this page whilst looking for a way to remove style sheets using jquery. I thought I'd found the right answer when I read the following

If you know part of the url then you can remove just the one you're looking for: $('link[rel=stylesheet][href~="foo.com"]').remove();"

I liked this solution because the style sheets I wanted to remove had the same name but were in different folders. However this code did not work so I changed the operator to *= and it works perfectly:

$('link[rel=stylesheet][href*="mystyle"]').remove();

Just thought I'd share this in case it's useful for someone.