I'm not sure if this compressor can be resealed very easily. It is possible that an a/c shop might have special tools and could accomplish this.
If not, you will have to replace the compressor to repair the leak. It would be a good idea to check the system for leaks using UV dye or a sniffer before repairing or replacing the compressor. It is POSSIBLE that what you are seeing is a power steering or engine oil leak and draining over the compressor.