You are generous. A 50% cut in government would be very nice.
1) Make a list of all the Federal departments and agencies that existed December 31st, 1959.
2) Make another list of all departments and agencies that exist today.
3) Compare the two lists and work to eliminate the departments that exist today that did not exist prior to January 1960. EPA, Energy, Education, DHS, and dozens of others would be dissolved.
Simplistic? Yes. The purpose of the exercise is to rethink and justify the existence of these entities. Trivia: how many existed when the Constitution was created in 1789?