If you have recorded a cue in a sequence, open the sequence editor. Go to the cue you want to edit and the attributes column. Hit [MODIFY]. This will open an editor for the attributes for that cue in the sequence. You can select the cells you want and then press [DELETE] at the confirm pop-up [MODIFY]. [UPDATE] then [ESC] to close the attribute editor.
If it is a sequence built from presets, you go to the Preset List and find the preset and attribute column that you want to edit and follow the above directions.
Take care,
JP