Apart from the CMOS, you also need to remove main battery and charger.
Waiting a minute with CMOS out is long enough, IF that laptop only has a Power-On-Password.
If not, to unlock the BIOS you'll have to take the mobo out, but leave it within the chassis.
Make a drawing of where the screws are removed from and tape them on it.
Then reconnect the keyboard and use two screws to keep the keyboard "attached" to the frame.
Only turn those screws 2 or 3 times, to avoid damaging the keyboard.
Attach only the charger, then hook up to an external monitor.
Find the password-EEPROM using
these pictures.
They also show which pins to use for the SVP-removal.
That EEPROM is partially 'hidden' under some plastic cover (can be lifted), as seen below:

Since it is on the bottom of the mobo, you'll need to somehow stand it up with the mobo-bottom facing you, or have someone hold it.
Get some sharp-pointed tweezers or similar and follow this youtube video:
https://www.youtube.com/watch?v=5z0HdLqgR_I
You may need 3 or 4 hands for that, but check that youtube a few times first.
Alternative: find another Thinkpadder in or around NY to do it for you.