You can edit the items in a Playlist by tapping the pencil icon in the top right of the Playlist page.
This puts the Playlist into Edit mode.
You can change the order of the items by dragging them using the handles that appear on the right of each row. Or, you can select the items in the order you'd like them to be arranged, then tap Actions and choose Arrange.
You can remove items by selecting them and tapping the trash can button. Note that if you remove an item from a Playlist it won't be deleted from the Presets library or other Playlists.
Also, while you're in edit mode, you can select multiple items and perform actions on them by tapping the Actions button that appears at the bottom of the screen.
Watch the video to learn more