If you’re new to the 3D Printer PID Tuning then the article link below may help to understand what it is and how does this work: https://all3dp.com/2/3d-printer-pid-tuning/
You can do it in the Notepad or other editor program, but afterwards it has to be uploaded to the printer.
In the file there is “Z-Probe” section, where you have to fill the new data.
Attention: Please take in mind there can be difference between the build plate width and the width of metal calibration part, as well with length of BL-touch sensor.
P.S. If you’re new to the 3D Printer PID Tuning, then the article link below may help to understand what it is and how does this work: https://all3dp.com/2/3d-printer-pid-tuning/