To edit a phase's name, phase-type (assess, train, track, maintain) make sure the edit data icon is toggled on. If you don't see the Edit Data icon in the top right, then you need to ask your Motivity Admin for permissions to edit past data. Then find the date of the phase line (transition) by hovering over the phase line. You will need the date so you can scroll to it in the timeline.
Then scroll down in the timeline to find that Transition. Click the transition.
Then click the pencil icon next to the transition to edit. You can change the name, phase type or date of the transition. Or click the trashcan to delete it.