Below, we can see our Playlists within the Playlist tab.

After we've selected a playlist to play, we'll come to the below screen. Pressing the music note brings up the options of: "shuffle By Artists", "Shuffle By Albums", "Shuffle By Songs", "Play From Top".

To edit a playlist, select the 3 dots icon, next to the song you'd like to remove. Select 'Remove from Playlist' as seen below.

Viola! The song is now removed.

You may also want to reorder your playlist, this can be done by dragging the icon on left side of the song and moving within the playlist.

You may want to make an edit to a live list, and receive this message below.

As the message indicates, Live Lists, are not able to be edited, because they are not user controlled, but Rocket Player controlled. You can find more information on live lists as well as live lists' frequently asked questions.