There is always the option of using the robotic arm to hold and maneuver starliner out of the way of the docking port. Once the software is installed to unlock or remotely. Just move the arm and grab onto one POS then undock it unpowered so no risk of impact use the arm to hold it at bay long enough to dock Crew 9 with extra seats and compatible space suits for the NASA peeps. The docking adapter on the front of both Dragon and Starliner are IDA compliant but both are in the active mode. SpaceX could send up a cargo Dragon with a dual mode IDA adapter ring on it then it can be the passive mode side and dock nose to nose to starliner still being held by the robot arm once docked to the junker release the robot arm and let that cargo Dragon pull the trash out to sea for them. You would never need anything other than the unlock software to work in that case.
starliner can not be grabbled by the robotic arm does not have fixture atached to it neither does dragon.