Although they sound similar, thought changing and thought calming are two very different processes, though they can be used in conjunction with each other. Basically, if you do not change your thinking process, you'll always have to do a lot of thought calming. Calming is for the moment, changing is for the long term.
You'll be referred into related items. For instance, beliefs are a form of thought. Negative chaining (under internal conversations) is a form of feeding one belief/thought onto another to produce a downward cycling. And, of course, it is all part of our internal conversations, with a section on the actual revision of thoughts.
Thought changing (see below) has a dramatic effect on having more calmness of mind. Changing beliefs is also vital. Thought calming tells the primitive danger reacting part of the brain that things are "safe", so it is less reactive - the brain actually changes its physical "wiring" so that it is also more automatic to feel calm and centered and takes little effort to maintain - this is scientifically proven.
METHODS TO CALM ONE'S THOUGHTS
This is a vital skill and practice that "reconditions" the brain's wiring system.
Read the Meditation page, summarizing the key methods and emphasizing the simplicity versus what people think it is. On that page it will refer you to Meditation Resources for easy aids and more in depth opportunities. Carefully study the list of Meditation Benefits and consider them.
Calming Self Talk And Intervention
Use the soothing statements and declaration contained in Dealing With Negative Thinking In The Moment (thoughts aren't real, I'm safe, this is useless, there are no emergencies right now, nothing truly urgent, I will not tolerate negative thoughts..).
This is vital because if you don't do it, then you'll constantly be repeating the negative emotions, trying to cover over the thoughts, compensate for them, experience bad feelings, and battling them (when there is no actual need to have a war!). Cleaning a toxic thought up only makes sense - and it's alot less effort than living with harmful and/or limiting thoughts.
Yet, many people don't even bother. They live as the passive victims of automatic negative thinking habits/routines. But the only way to live a good life is to be proactive and to drive this to full completion, to full mastery, with a complete replacement that is installed as a new habit.
Read these and do the actions, never allowing a negative conversation to be continued AND replacing it asap, using the forms provided (see Beliefs Forms Directory/Links to access the right form).
An example of a form you might use would be:
you locate your thoughts and emotions and address alternative ways of
thinking. Note: This type of thing can be kept accessible in the
Reminders/Inspiration notebook, so you can instantly correct your thinking
if the same thing pops up again - or refer to a form where you already had a
corrected conversation formulated.
Read those sections, but start immediately on using at least the Thought Change Record to start replacing the garbage thinking that most of us allow and are engaged in.