wean
To slowly help someone stop needing something they depend on.
To wean means to gradually get someone (or yourself) accustomed to doing without something they've depended on. The word originally described helping a baby transition from drinking only milk to eating solid foods, but it works for many kinds of transitions.
Parents wean babies off milk over time, slowly introducing new foods until the child no longer needs to nurse. You might wean yourself off video games before a big test week, playing a little less each day until you can focus completely on studying. A coach might wean a basketball team off one strategy and toward a new one, making the change gradually so players can adapt.
The key idea is gradual change rather than sudden stopping. If you quit something cold turkey, that's not weaning. But if you slowly reduce your dependence over time until you don't need it anymore, that's weaning. Someone might say they're trying to wean themselves off staying up too late, or that a country is weaning itself off dependence on foreign oil.
The process takes patience and consistency, but it works because it gives people (or animals, or even whole organizations) time to adjust to a new normal without the shock of an abrupt change.