Manifold off, now what?? Lol...newbie question

Put towel down on lifter valley under heads and along bottom.

Get a shop vac and suck directly where you are scraping on front and rear rail till they are perfectly bare metal.

Then clean rails with carb or brake cleaner.

Build a duct tape bowl between the front and rear rail once it is perfectly clean.

Stick paper towel down each intake port.

Then start carefully scraping debris off the intake surfaces of the heads while holding shop vac there so it sucks out all dislodged debris. Use small diameter nozzle such as 1.5" to increase velocity and accuracy of suction.

Work slowly and observe any particle that does not get sucked up, you may have to find it.

Once intake surfaces of heads are bare metal from scraping, then friggin blast them off with carb cleaner.

Pull paper towel out of each port while holding vacuum cleaner nozzle there. May get tricky for a sec while the vacuum cleaner eats the towel. Anyway, if the towel is soaked with carb cleaner you may not want it in a vacuum cleaner because of concentrated vapors so you might want to manually pull it from each port and just vacuum out the port secondly.

Then I have no idea, probably put your gaskets, gasket sealer and parts back on.

You may need an assistant who can crawl around on an engine bay.