#### MuseScore -- Index -- Brackets

Remove
Select the bracket and press ``Del``
Add
Drag a bracket symbol from the bracket palette to an empty space in the first measure of a system.
Change
Drag a bracket symbol from the bracket palette to an bracket in the score.
Edit
Double click on a bracket to enter `edit mode` , In `edit mode` you can drag the hight of a bracket to span arbitrary staves of a system.