Delete and rename sequences
Sequences can be removed from the alignment by right-clicking the label of a sequence:
right-click label | Delete Sequence
If you wish to delete several sequences, you can check all the sequences, right-click and choose Delete Marked Sequences. To show the checkboxes, you first have to click the Show Selection Boxes in the Side Panel.
A sequence can also be renamed:
right-click label | Rename Sequence
This will show a dialog, letting you rename the sequence. This will not affect the sequence that the alignment is based on.