Well, since you know it's bad, the first thing to do is CUT THE PINS. Then remove them one at a time.
With the thermal pad, you might have to heat from the bottom and possibly the top too. EPOXY really doesn't like to conduct heat.
If it was glued in anyway, twisting would release the bond.
My very first SMT solder/desolder was about that size, but no thermal pads.
This was before the ROHS noise. Once the IC was removed and the pads cleaned up and tinned if necessary I used a technique suggested by a friend.
I used 63/37 solder which is basically imperative for SMT stuff of that ERA. The solidus and liqudus points are identical.
So, I tacked the corners AND..
get this. I turned everything UPSIDE DOWN so the chip was above my head and then just dragged solder across the pins. Later, I turned it the right way and removed whatever bridges there was.
In some respect you might be able to get a re-work stencil and re-flow that way.
http://www.google.com/url?sa=t&rct=...ZI4AQ1nmq1k42sw&bvm=bv.74894050,d.cGU&cad=rja
Here
http://www.zeph.com/ is an interesting place to hang out to get some ideas.