You are looking for pins labeled "KBC" (Keyboard Controller) or "SDA/SCL" near the EC. Based on community schematics for the M720q (IBM Lenovo FRU: 5B20S43790 or similar), you need to short pin 8 (GND) to pin 1 (SDA) of the EC's debug header.

Q: What if I forget the BIOS password on my Lenovo ThinkCentre M720q? A: If you forget the BIOS password, you can reset it using one of the methods outlined in this article.

When you install the new chip, the system will have a completely clean BIOS with no password. You will need to input the machine's serial number (on the sticker on the case) using a tool like AMIDEWINx64.exe to restore full functionality.