To install an outside water hydrant, choose a location, and dig out a hole all the way down to the water line. Shut off water supply to the line, and drain water from it. Cut out a part of the pipe, and insert a tee in it. Place an adapter at the bottom of the water hydrant, and secure it using Teflon tape and some joint compound. Connect the tee to the hydrant using pipe pieces and glue.
When digging the hole, make sure that it is deep enough to fit the tee in it. If you are digging close to the water line, be careful not to damage it. To get rid of water in the line, use a hose bib to drain the water. When attaching the tee, make sure that it is facing in the correct direction to attach to the hydrant. Hold the pipes together for a while to allow the glue to set.
Once the glue is dry and all the pipe pieces are securely connected, turn the water on, and let the system run for a few minutes. Make sure all the parts remain in place and there are no leaks. Place some rocks around the drain valve on the hydrant, and fill the remaining space with dirt.