Mopeka Water Level Sensor and Beta Cerbo Firmware is very difficult to calibrate

I have a Mopeka water level sensor on a water tank and a late model cerbo. Firmware is the Beta 3.70 ~ 61. I am trying to calibrate the sensor custom level points. I cannot delete the current sensor points to enter a new one. Then I try and delete the sensor and start over. I turn off the sensor and then go and delete unused items and reboot the Cerbo. The sensor is still in the setup and all the levels are the same in the custom shape. How do I delete this to start over or delete custom shape points to calibrate. There is no way to delete the sensor or the level points in the custom shape settings. I have tried everything and have been working on this for days.