Before reaching for JTAG, always try Samsung’s official account recovery or contact the previous owner. If you do proceed with JTAG, make a full eMMC backup first, and never work on a device you do not legally own.
: Solder the CLK, CMD, D0, VCC, VCCQ, and GND wires to the motherboard's ISP pinouts. samsung kg lock remove easy jtag
Even with "easy" JTAG, issues arise.