Your inner strength must first be present and felt (by you and others).
You would “want to do it” from the heart ; from the inside ; from  your gut !!

Only then, can your ” physical self”  take the needed action with full conviction to do things differently in a disciplined and structured manner (as determined by your mind).

Your behavior and habits will automatically react in alignment with your thoughts. You will be focus.

Your “demonstrated outward actions”  will tell a lot of your inner strength
and the intensity of your desire to change. Your determination and peserverance will be prevail.

Change cannot be forced onto you. If it is, it won’t last and the desired results will not be optimum. Over time, you will retreat back to your old self.

You must want to do it yourself and not because someone else told you to do it.

Hence , convinced yourself first (you must) before you commit to others that you will change.

Then change will happen Very Quickly. It is a myth that change behavior takes a long time.

It’s all in your mind.