Manifold off, now what?? Lol...newbie question
Lay some nice clean rags, or a garbage bag or something similar in the valley, tuck it up around the pushrods under the edge of the heads. Stuff small rags in the intake runners and coolant passages and scrape away. Scotchbrite and brake clean work good for a final clean. Remove all large debris, use a vacuum to remove as much small bits as possible. Remove all rags from the engine and ports. Check again that you have everything removed. Reassemble. After the first run replace the oil and filter and you are good to go. Remember to put a little sealant on the intake bolts to prevent oil leaks past them.