All you have to do is take a little off the upper right corner of the heatsink.First size it up to see about how muck to take off, just suspend it in place to get an idea. You might be able to just file a little off the corner, mine needed a little more. This is what I did...
First, I took the fan/shroud assembly off (4 screws) and also removed the heatsink retaining clip)so it couldnt get messed up).
Then I took the upper right fin(then corner that needs the room) and wiggled it back and forth a few times till it broke off at the base. You may not need this or you may need to take off 2, whatever it takes.
I then took a hacksaw and cut the corner off, then took a file and smoothed it out.
Then test fit it and put it back together, it only took about 10 mins. to do once the heatsink is apart. But while it was apart I also lapped the bottom with 400, 600, 1000, then 1500 wet sandpaper on a piece of glass so it would be smoother.
It is very easy and like I said some guys just had to file off the corner to fit, I wanted a gap there just to be sure.