KING250R,

Drain the trans. oil from the drain bolt on the bottom of the engine.

After it has drained, replace the drain plug.

There is a check bolt on the side of the engine. Remove it.

There is an oil filler cap on the top of the engine case. Fill with oil until the oil runs out of the hole where you removed the check bolt.

Reinstall the fill plug and the check bolt.....you are done.

The trans. oil will not run low unless you have a gasket leak, bad crank seal, or if it is waaaaay overdue for a oil change.