for you situation, I would use the Castlevania Judgment method, since you need to uninstall a bad wad. It also is more flexable method as you can install/uninstall multiple wads and exit to the HBC.
The game is not the most popular so- You could rent it, or torrent it. But the fastest way would be from usenet. You could have it in a couple of hours. Usenext has 14 trials from about a buck, and if you pay with paypal it does not auto renew. Its a good deal.
Slow Torrents- The Pirate Bay - The world's most resilient bittorrent site
There are many on usenet