The small connection part can be removed and put onto the new valve. It is held in place with a couple clips and one lose, the entire things will slide off the ends of the terminals.

The connector is usually held in place by a clip on the underside and requires the use of a small flat blade screwdriver to separate from the solenoid. This connector is standard on many of the newer valves and is designed to be removed when the valve needs replacement. This allows the same valves to be used whether the unit has the new smaller connectors, or the older 1/4" connectors. If you are unable to get it to separate without breaking, then cut the connector of the ends of the wires, and purchase a coupe 1/4" crimp on connectors to put on each end of the wires. The circuit is AC so it doesn't matter which wire goes to which connector.