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

I got the TBI intake manifold off, and I want to clean up the mating surfaces, remove old gasket material, etc, so I can put on the Weiand intake. But looking at the top of the engine, it looks like I'm going to have to deal with all the crap going down into the valley of my engine. I've never had an intake off, so, yeah, pretty basic for you pro's here 😁 Care to help me out again? How do I proceed without getting crumbs down into the cam / lifter areas?

This is a 1990 LA block, 360, with only about 26k miles on a remanufactured. I was not planning on pulling the heads either. How can I scrape off the old gasket without creating another problem?:prayer: