Here's the principle: if you're not wllling to die, you have no chance of being reborn. If your inner child doesn't die, there's no room for an actualized adult to take place.
Now here's the theory: to strategically kill parts of yourself, you need to first overcome the trauma.
I unintentionally underwent a mental extreme sport this past week. I revisited and re-lived several childhood traumas under the suspicion that there were leftover anxieties that has been leeching my psyche and became undetected burden.
It was so immersive I couldn't unplug. It regressed me back into the mental state of a trigger-happy teenage mind, the worse kind there is.
At least I made progress in reliably reproducing the traumas. The next quest is about steeling myself against them.
I haven't found a clear answer to that. The closest one yet seems to be the most cliche sounding one: love yourself.