One step at a time for me. I've been in major purge mode for a year now, going in waves. First it was the obviously completely awful stuff, like 20 year old jackets and things I hadn't worn in 10 years. I'm telling you, my closet was a disaster.
After that I went by seasons...purging the not awful but still bad level at the start of the season and the medium but not happy things I didn't wear at the end of each season. That's where I ran into some trouble because I purged all but about 4 summer tops last fall, assuming I could replace them when the time came, but have been having a hard time finding colors I love this spring! I'm making some progress though.
I still have some things I'm questioning but I'm at the difficult place now. For instance, a dress I was so sure I didn't want to wear again, I had to end up wearing recently because I hadn't found anything better. I'm at the point where some regrets could happen, whereas the stuff I gave up earlier in the process was not possible to miss. So although I would really like to purge even further and only have things I love and want to wear, I have decided to now start replacing first and purging only then.
So yes, very step by step.