New energy use feature - delete date

I have just got my energy use up and running with the PZEM-004T, however at setup I did not enter the costing correct rather than 0.15 per KwH , I entered it without the decimal point , so now my 1st few days of use are totalled up incorrect, I have tried deleting the PZEM and re adding it but the wrong total from the 1st few days is still there, So does anyone know how to clear the saved data? so I can start again from scratch?
Thanks

You have to edit the recorder database statistics table.

I have googled it and cannot see anything specific to that, could you please point me to the correct area?
thanks