This will take about 2 hours. You will be working on this a while.
First, I move it up from the floor to a decent work height. Maybe with 2 milk boxes high. Then, I put newspaper in a 3 foot radius around the work area. Then, I get putty knives, scrapers, and knives from the tool box. Grab a trash can and paper towels. Grab a stool to sit on. You will be scraping for an hour.
First, you will scrape off the layer of dirt/oil (which my high school friend Steve called "gorkle". Then, you go to the parts store and buy 3 or 4 cans of brake cleaner and a roll of paper towels.
Clean off the thin film of greasy dirt. On some lower surfaces, you will find a clear waxy yellow coating. This was sprayed on the cars before they left the port in Italy. More scraping and rubbing to remove the wax.
When it is clean enough to eat off of, now you can take it to spray car wash.
Only spray wash it if you plan to disassemble it. Any water that gets inside will cause a problem. If you spray wash, make sure to plug the vent on the shift housing because it is easy for water to enter there. Now, drain the oil and
Either disassemble it or refill it with new trans. oil.