[HoosierDaddy]

Hi Les, The plumbing is connected under the sink so that either faucet can supply water to the spout. The inner seal on the right handle is leaking allowing the water to escape there rather than out the spout. They either have a cartridge or O rings to effect a seal. I would turn the water off to that fixture and remove the handle etc. The trim ring that is just under the faucet handle will probably come loose by gently prying on it or you may be able to unscrew it. You might need to wrap a rag around it and use channel-locks to get it loose. With it removed you should be able to see the "hex" area. Removal with a wrench should yield the "guts" of the valve. You can probably take the "guts" to a hardware store for replacement parts.