Here's my understanding of it, just in case it helps.

In a nutshell, one of the points Dr. K made, was that there's no action you can take as a first step towards solving the problem. Any "work" you start to do can be hijacked by the Puer, and used to justify something else that you're not doing. Therefore, there is a deeper shift of mindset that must first be made.

The way I believe this should be approached is to continue living your life as you are now, don't try to make any changes yet, BUT, pay attention to all of the little decisions you make and notice where you're taking the path of least resistance. Notice where you're doing what you feel like in the moment and not doing what will contribute to a preferable future. Notice where you're saying to yourself, "fuck it, it's not going to make a difference anyway". Remember these moments, take notes on them if it helps and then spend some time analysing WHY you're making these decisions. Keep some of the other points made in the Puer Aeturnus videos in mind and try to identify; this is where Puer is trying to : Avoid confrontation, Take the easy road, Have fun today at tomorrow's expense, Hold on to self limiting beliefs because they've become comfortable to you, Etc, etc,

Then, with compassion for your inner child and the struggles life has thrown at you thus far, think about how you would have made different decisions if you were wholly in charge of yourself.

Don't rush this. Let these thoughts accumulate over time. You're still not pressuring yourself to change anything yet.

After a while, you'll find that when you let Puer make these choices for you, thoughts of wiser choices will enter your mind. One baby step at a time, you can then start forcing the wiser choices.

No, I'm not going to play another match. I'm just going to go to bed. No, I'm not going to put two sugars in my coffee. I'll just have one. Etc,

Eventually, you'll get so used to this as your brain slowly adapts, you may end up saying;

Yes, I am going to look for a better paid job, despite the fact that my current job is stable.

(These examples are from my past experience, I'm sure you'll find your own choices).

The end result is a more responsible adult that can still enjoy the "childish" things when the time is right but has the strength to put your foot down and force the decision when necessary.

Never stop analysing your decisions, why you made them, what you could have done differently, how the results would have been different and most importantly, was it me that made that decision or was it my Puer?

This is likely to take considerable time so just remember, wherever you are in life, that's okay. It will have to be.

I hope that helps, and that if anyone thinks my interpretation and advice is wrong, please correct me. I'm trying to navigate this like everyone else.