Whenever we want to make changes, motivation is always a big thing to consider. In my reading, I have been amazed how much science knows about motivation, and how little of this has made it into the wider sphere.
A key theory of motivation is self-determination theory developed by Ryan & Deci. They established three factors needed to fulfil our basic psychological needs. They are competence, autonomy, and relatedness. When looking to change something, it is worthwhile aligning one's strategy with those three.
Competence means picking a change that we can actually achieve, and one that we feel able to achieve. If we don't believe that we can make the change, then we won't!
Autonomy means having a goal that really is ours - either pleasant in itself, or something that clearly leads to a desired goal, or paired up with something nice. Having goals because others have told us to do them is less likely to work.
Relatedness means being with others, sharing the goals, and using sociable strategies. Goals that we hide and do by ourselves are less likely to succeed.
People can and do change all the time, yet change is hard. Self-determination theory gives a guide on the types of strategies that are in general more likely to work.