Spray bottle of Simple Green mixed 50/50 with water. Full strength for more difficult areas. Light water spray to wash off cleaner and residue. Cover or protect sensitive electrical components. Don't spray directly into or onto the alternator. I use several sizes of paint brushes to reach difficult areas and have plenty off rags and small towels available. Lots and lots of elbow grease along with several busted knuckles. Once it is clean and dry, I use CD2 Engine Protector (if you can find it). Otherwise I use Gunk Engine Spray Shine over the entire bay except the belts and alternator windings. The first time you do this it will take several hours or more. Keep it clean and you can dress it up in about an hour. For last minute touch ups at car shows, I use ICE Spray Detailer. It works inside the engine bay, too. Hope this helps.