You don't stop thinking. This is the process...
First you must have a proper mantra chosen for you.
The mantra is charming to the mind. You easily start to think the mantra and as you do you begin experiencing the manta on more and more subtle levels. The result is that the body begins to slow down. As the body begins to slow down it begins to dissolve stress which manifests as some activity in the nervous system. That activity will be experienced as some form of thoughts. As long as those thoughts are there the nervous system is purifying itself. When that stress is gone you may realize that you are not thinking the mantra and very easily come back to it. Never concentrate on it. Never fight thoughts. The mind will naturally go to it until some other purification activity begins in the nervous system. This process allows you to experience the mantra on more and more subtle levels leading to experience the pure source of though which is pure consciousness. Thoughts that come are not the enemy but the ther result of the nervous system purifying itself which leads more and more to the mind being able to experience pure absolute unbounded consciousness while also experiencing day to day activity. That is a blissful and graceful state.

This process is very profound and very easy and natural if one learns properly from a trained teacher who can choose the correct mantra for you. and guide you through the first few days of the practice.

Author's Bio: 

Sri Tulasi is a professional astrologer and motivational speaker having more than 15 years of experience.