It is possible to create an energy body of yourself and then transfer consciousness into it. This is not a matter of days or even month but years, not really difficult task but you need to practice at least one hour everyday morning and night to have some results.
A good practice as base is the nyasa yoga ( this is an huge subject and many possibilities are available) and focus everyday on each part of your body chanting the corresponding mantra it will unlock channels, chakras and sub-chakras points even the subatomic channels.
You can add hand mudras and Kuji In as each mudras work simultaneously on channel and corresponding chakra points.
It’s very important to do qigong to help the qi to circulate and also to choose wisely which qigong routine can help to release your personal blocages.
A kundalini meditation is very important and also breathing, many exercise can be found on these subject. Try several of them until you find the one who works the best for you, there is no perfect formula for everyone, you need to test what work or not for you. Write your observations on regular basis.
After few month of practice you will feel some new energy current flowing into the body and mind new abilities and enhanced consciousness, after years of practice you can experience a kind of flow into the whole body at same time, like electrical current or something like that then you start to feel the energy body into the physical one. This is a curious feeling, you start to feel a new presence who is yourself but a more potent/alive version of you.
When you reach this stage you have to train your consciousness to go into this body for several minutes then come back into the physical one progressively you will be able to send the consciousness for larger amount of time and even maintain the consciousness permanently into this energy body. There is no exercise for that it’s a natural process, you intent to do it and with focus it happens.
It doesn’t mean that you forget the physical body. Both of them exist at same time but you don’t use anymore the physical body as your main vehicule and control it with the new energy or qi body. When the death is near you it becomes easy to maintain the consciousness into the qi body and cut the link with the physical one.