Removing the carbon is pretty simple if the parts are off the bike; just soak in solvent until soft and then scrape with a non-scratching scraper (plastic, wood, etc.). Cleaning the piston crowns is a little more complicated if still in the cylinders, but the same idea applies. Since you can't just soak the parts in a pan of solvent, use solvent on rags to soften the stuff and then carefully scrape with a non-scratching scraper. Do this with the piston at TDC, and when finished rotate the engine so the piston is down a bit in the cylinder and clean out any gunk that dribbled down on the cylinder walls.
I wouldn't worry about a light even coating, as that is normal and it will quickly return even if you clean it down to bare metal. You don't want uneven or heavy deposits, however, as those can cause hot spots which can lead to preignition/detonation. Heavy deposits would lead me to look for causual factors such as oil burning (valve stem seals remain the number one suspect for that), excessively rich fuel mixture, or lots of low speed operation while using fuel with insufficient levels of cleaners. Try a better brand of fuel. And don't let anyone convince you to just button it back up and then inject water into the hot intake with the engine running at 2000+ rpm to "blast" the carbon out. While that was a common method in the old days, using a mist sprayed into the carb throat, it has the potential to cause damage if done incorrectly. Much smarter to clean the parts while the engine is apart.
Jerry