Just to give a short foundation for my questions, I am a struggling 70 year old with an acquired 3d printer because my life wasn’t complicated enough. I upgraded the Ender 3pro to the new 4.2.7 board so I could use the BL tough sensor. My eyes are crossed from watching so many You Tube videos ! One of them directed me here, for which I am glad, but I still have some basic (stupid) questions. 1) How do I open the file in Arduino to make a necessary change? 2) Once I’ve made the change what do I do? 3) Is it for real that I have to use an 8gb SD card? 4) Does the SD card have to be fresh with only the file to update on it? Thanks in advance for any assistance this group can provide!