I'm not sure if it's possible to exercise a function if you look at functions as attitudes, but you can certainly pick up skills from other people and incorporate those into your life, no doubt.

 

Do things you don't like to do.

 

That's it, more or less. It IS possible to gain awareness of each function as it manifests in you and to grow those functions... just understand that certain functions can't always work together at once, and the patterns you structure your life after will follow the functions you rely most heavily upon.