Stop pursuit, stop snooping/checking emails etc, not hang around waiting on calls, not trying to arrange meet ups, GAL, focusing on your own career/job, making new friends etc. I take it these are cold, hard things that coukd be done to detach. Are there any other practical things that can be done? Being.neighbourky in interactions etc?
Re-read Zew's excellent post above, Alpha. You're still viewing detachment as a method or a set of tactics. It's not . . . it's more of an ATTITUDE, a MINDSET.
The way to adopt a mindset is just to . . . well, adopt it. It's a DECISION you make, a discipline. And then the longer you keep it up, the more it becomes second-nature to you.