Method 2. Remove the vacuum chamber by water hammer action
1. Hold the bottle firmly with your free hand. Hold it at about a 45-degree angle without covering the bottom of the bottle with your hands.
2. Tap the bottom of the bottle with the center of your palm. This is called water hammer and can remove the vacuum chamber by increasing the pressure around the lid. Hit it hard enough to remove the vacuum seal, but be careful not to hit it hard enough to injure your hands or break the bottle. When moving into the vacuum chamber, there will be a "pop" sound.
Open the cap. Hold the bottle properly and twist the cap to the left. Vacuum chamber will open easily if removed correctly