Take a grinder and grind off the bolt on either side of the spring hanger. Take a punch (bolt, socket extension, anything hard enough to count) and whack the bolt first one way, grind flush, then the other. when you get as far as you can doing that, take a pry bar and slightly pry out the spring hanger on either side. Twist the spring back and forth and it should fall right out.
Hope that helps.