Having a boundary is vital to being able to walk through this world as a sensitive person. It is a choice and must be maintained.
You want to clear your energetic field before you begin. Then calling your guides to assist you you simply ask that your old boundary be removed ( you can repair the old one but I have found this to be a waste of time) ask that the energy of the old boundary be transmuted into love light and beauty.
Then ask for an upgraded boundary that is clear and strong. Or you might feel the need to make it colors or reflective. It is your boundary play with it. Know that it is a choice to put it there and maintain it. You can take it off when you are at home or in nature but then you need to remember to put it back on. When you have an expansive experience you will need to upgrade it because of the stretch marks that happen.
You may find the boundary uncofertable at first because it dulls your sensitivity. I found this to be true for me at first. It was so quiet in there.
In order to clear and be responsible for your energy field you need to maintain a boundary. This will alow you to stand strong and be of service to this world. Without it you live in a state of overwhelm and angsity. You are also vonerable to entity's and gost attachment. Which is a truly unpleasant experience.
I hope that was helpful. Love and blessings to all you brave sensitive souls.