If you would like to create your own Brohoof icon that is compatible with the ones I've created, you can use this for placing the text. They are right in the same location for the ones I made. You should draw your pony with their hoof under the text for best results. And also, remove the half that you're not using for that particular icon, so erase "bro" if you're making the hoof part and erase "hoof" if you're making the bro part.
And for the less artistically inclined of the herd, here is a pony template you can use: [link]
Edit: The image that the text is to be placed on needs to be 896x896 for proper alignment. The first semi-transparent pixel in "hoof" should be placed at 495Y.