Choose the appropriate plate weight taking account of your fitness level and training type. Lie on the bench on your belly and let your head protrude from the bench. Grab the weight and put it on your vertex. Hold the weight with both hands all the time.
From the starting position move your head upwards while contracting your neck erectors and then downwards slightly below the starting position. Do the required number of repetitions. Inhale going down and exhale while stretching your neck muscles.
Do not overestimate your abilities when choosing the weight. Your chest and whole torso must be firm and fixed throughout.
The number of repetitions depends on your type of training.
Do not use heavy plates. This exercise can potentially cause neck injury. Also, raise your head slowly and refrain from jerking.