Firstly you need to find a space that has minimal noise and is very private.
Then you need to sit down, prefrebly in a comfortable position and just start takeing big breaths in and out, For about 5 minutes. Then take evan bigger breaths in and out as big as you can for about 10 seconds.
After that breath normaly or as comfortably as you can. Then starting from your toes and fingers pull all your energy and life force and out them reserving deeper and deeper into your body so that you have nothing left in your arms and legs and its all come into your torso. From there imagine all of it being pushed really hard into your head starting from your pelvise going up.
So you reach the point that all of your life force and energy are squished into your head and you cant feel anything in any other part of your body. From there breath deeply a bit and after about 1 minute start to gradualy push your life force back into the rest of your body again.
Tip: make this whole process really slow and when pushing your energy back into your hands and legs take it really slow. And make sure you imagine every bit imaine the life force going back into every finger and toe.