The code controlling an object's state transition are complex.
Replace conditional code with State classes which handle specific states and their transitions.
Complexity
easy
Checklists present a proven order of necessary refactoring steps and are especially helpful for beginners.
If you feel comfortable with a refactoring, there is no need to follow each of the steps literally; you can often perform multiple steps at once or skip some.
We suggest to try the recommended order at least once; this will often provide new insights - even for seasoned developers.