In air layering two parallel cuts about an inch apart around the stem and through the bark and cambium layer. Connect the two parallel cuts with a long cut. Then remove the ring of bark, leaving the inner woody tissue exposed.
https://lifeandagri.com/asexual-propagation-of-plants/
Just a word of caution. I learned by mistake that if you remove a ring of bark too close to the base of a plant without any other stems or leaves bellow the cut, you have effectively girdled the rootstock and there is a good chance you will lose it. The reason for this is that the rootstock is still sending water to the top, draining its stored energy and nutrients, but the top is not sending nutrients back to the rootstock and it starves. So only use this method on a multi-stem plant, or at least above some leaves that will be left with the rootstock.
