I am way way way at the beginning of all this so I am not presuming to tell people with more experience how they should do it, only adding how I am working at this, since I am working my 6th step.
I am currently examining my list of character defects, how they play out in my life, what my life might be like without them and which spiritual principles I might apply instead.
Sometimes all I can do is NOT act on a character defect impulse. That's a start, to put it down.
If nothing else, I get the experience of doing something differently, a small taste of what life might be like if I no longer reacted to a situation the same way I have before.
I get a chance to see how it feels to do something differently. The initial impulse is still there, but if my new response, generates a result that I like, I think I am more apt to choose it next time. Positive conditioning.
Sometimes it's just a case of "at least do no harm" that's a big step forward for me.
At this point, my character defects have not been removed but my seeming NEED to act on them has been lessened. I am willing to NOT act on them (at least some of the time) and see how that works out. A degree of compulsion has been lifted.