Adjusting dumbbells is a fundamental skill for any weightlifter or fitness enthusiast aiming to optimize their workouts. Firstly, ensure you have the correct type of dumbbells that allow for adjustment, typically those with screw-on collars or spin-lock mechanisms. Start by setting the dumbbells on a flat, stable surface such as a weight bench or the floor, ensuring they won’t roll away during adjustment. Next, loosen the locking mechanism securely but not completely to prevent accidental slippage while adjusting. If using screw-on collars, twist them counterclockwise to loosen, whereas for spin-lock dumbbells, turn the lock in the opposite direction of the threads. Carefully remove or add weight plates as necessary, ensuring equal weight distribution on both sides to maintain balance.