By addressing your shortcomings.
- First you have to be aware of them.
- Then you have to be willing to address them.
In rare cases you may address your shortcomings by accident (this is not a sustainable form of improvement).
In rare cases you may be prevented by some structure of reality from fixing them (don't delude yourself into thinking you are in this situation when you are not).
So if someone or something is not improving, the questions to ask are:
- Are they or you aware of their shortcomings?
- If they are: why is it that they refuse or can't address them?