Life-Size Erector SetBy Rabbi Jack Abramowitz
G-d told Moshe to erect the Mishkan on the first day of the month of Nisan. He should place the Ark behind the partition, set up the table and light the Menorah. The altars and the basin should be put in their proper locations and the courtyard enclosure should be set up all around. Then, Moshe should use the anointing oil to sanctify everything for use.
Aharon and his should immerse in a mikvah, after which Moshe would dress and anoint them. After that, they’d be all set to serve as priests. (Any descendants born after that would be born kohanim and not require inauguration.)
Moshe did all of the above.