i literally just copied and pasted and then wrote in the brush BMP name.
but basically to add the new BMP you’ll have to write it in much like i have will all these extra brushes. nf (right click and make sure to open it with notepad) and you’ll see a list of brushes that are currently installed into your SAI. it’s usually in BMP format and you can just drag and drop it in. elemap is where you will place any specilised brush shapes that may be needed for your installed brush. Its a little complicated but installing brushes into SAI can be easy when you understand how the brushes in SAI work with the SAI folder.