Power supply for Raspberry PI touch screen

[ocejo 117]

I've having nightmares with this i have the same problem but i'm just starting, i have basically no idea of the procedure can any body pleas describe step by step how to get to /boot/ directory, is it over Debian on the tinker boad, is it on the sd card over windows (it can only read 1 partition with no such directory), is it over terminal in windows using adb? or terminal in debian os? if so how do i extract (code) the file so i can push the new one?

realy hope you can help me thanxs