How do you replace brake booster on a 1997 Volvo s90?

To replace the brake booster on a 1997 Volvo S90, start by disconnecting the negative battery cable and removing the brake master cylinder from the booster. Next, detach the vacuum hose and any other connections to the brake booster. Remove the mounting bolts securing the booster to the firewall, then carefully pull it out from the engine compartment. Install the new booster by reversing the removal steps, ensuring all connections are secure before reattaching the master cylinder and reconnecting the battery.