As far as I know the battery was not even removed from my car all information they collected was from logs and diagnostics through the car. What I was told BMS sometimes is getting voltage readings where it should not and the pack should be replaced. I do not think our Service Center takes packs appart. They do replace contactors because my friend had his contactors upgraded at the facility. Additionally they charge 3.5 hours of labor to R & I the battery. Waiting for call back on the LTE upgrade information, will ask to get logs of codes emailed to me .
The contactors are in the pack. You have to drop the pack and take at least some if it apart to replace them.
"voltage readings where it should not" doesn't make much sense. If it's leakage voltage, that could just be moisture in the connector.