After buying a new iPhone I was struggling to reconnect with the Remote App. until I came across these instructions (thanks to iNprum from Speak EV forum).
If like me you have had problems trying to find out how to remove old devices here's how:
1. Enter car, close door, no foot on Brake!
2. press power switch once ( gives orange light )
3. Put Hazard's on (the switch marked with a triangle)
4. Press the Lock and unlock buttons on remote total of ten times start with Lock, so lock - unlock etc
5. Now do same again but 20 times ( you should hear a single bleep )
this will clear all devices from the car / app