Once stitches have been selected, you can delete them or split them, To split them, click the ‘Split’ button. This will create a separate design for the selected stitches. It will also remove the stitches from the current design. If your design is lettering or a Library design, this process will convert that design to stitches so you will not be able to adjust that design the same as before.

Above, the design has been split, and the crown was copied and pasted.