Its not worth the legal issues. Older Force keys go pretty cheap on ebay. I just saw a 2006 key for $10 and if you check every so often you can find even better prices. Ive seen 2007 keys for as low as $15 shipped for a lot of 3.
But to answer your question you would have to program the old key with a data dump from the newer key which requires special equipment. Then you would need to modify the software which is encrypted, so you would have to decrypt it before you can modify it.