@Chilt I received my carbon fiber Neewer gimbal head yesterday, and was trying to figure out how to take the cap off as well. I finally figured it out, so thought I'd share. TOTALLY worth it, by the way!
1. The small circular cap is on by a strong adhesive, so you'll want to heat it up. I boiled a pot of water, let it cool down a bit (didn't want to test the carbon fiber) and submerged the end for about 45 seconds at a time.
2. When you put it in, you'll see air bubbles escaping from the small circular cap. Keep note, because that's where you're going to want to pry (yes, pry). You're going to have to make a small mark in order to get it off, because the cap is soft metal, sorry.
3. Once out of the water, wedge your flathead into the spot where you saw the bubbles, and begin prying (I recommend using the smallest flathead you have vs a knife, because of the amount of force needed. I went as far as to file mine down for a thinner/sharper edge. You only have a couple of minutes at a time to pry, so act quickly and carefully. It WILL come off with persistence, I promise! The heat also loosens the main bolt in the base!
Five recommendations when working on yours...
1. Plan on spending 2-3 hours working on it. I didn't want to break mine so I it took slow and spent about 3.
2. Use paint thinner (I used an odorless version from Sunnyside) to break up the factory lubricant. Worked like a charm.
3. Wear gloves! The factory lubricant does NOT come off easily with soap and water.
4. Remember where the spacers and bearings go. There are only three sets (each containing two spacers and a bearing), and I still had to watch a couple of video to make sure I was putting it back together properly.
5. I used Lucas White Lithium Grease. It might have been a little over the top, but it worked well. The base now spins freely and smoothly, and the pivot nearest the camera, while still not as "spinny", is 10 times better than it was before.
Good luck!