Removing the words “I Should”, “I shouldn’t” and “I can’t” out of your vocabulary. What to replace them with?

I recently heard a coach say something like the following, “Take the phrases, “I should, I shouldn’t, and I can’t” out of your vocabulary; they aren’t true.”

This can apply to many things (weight loss, addictions, behavior towards others).
I like the thought, but I missed the part as to what we should replace them with.

What phrases/ideas would you recommend we replace them with?