This should be easy to do: get a goat claw cluster with single pulsation line (and of cause the milker line too), replace the cow cluster from the line and connect the goat set to the bucket/pulsator. You are pretty done with it. If your cow cluster has a double pulsation line or 4 pulsation lines, you need to connect only one to the goat set, and block the rest of the outlet(s) at the pulsator.
The vacuum level or the pump does not need to get changed a bit.