For me i put a shortcut of task manager on the start screen, so i just open it and close IE. The above mentionned method works great for other programs/apps. I find that it needs a little practice to do it. I drag down from the top and in the middle of the screen i stop and go up a bit and then go down. That works for me but it might be different on other device.
It's a bit tricky if you have a raised bezel around the screen, it's horrid....
To get it, you kind of need to start slowly down from the top and try to grab it down. There's also swiping in from the side to bring up a different app, you can grab and try to drag that down too.