Hi Maxpower3 ,
thank you very much for your guide, I have succesful removed the supervisor password from my T490 NM-B901, even without removing the MB. I removed the SSD, my additional RAM and the battery before the procedure.
To help others as well, I have grounded the pin 10 with 12 on J9301 wich is next to the additional DDR slot.
Attaching some pictures for clarification.
Good luck! 😉...