To install the drum on Brother Printer, ensure that the machine is turned on. After this, you have to open the front cover and remove the toner cartridge along with the drum unit assembly from the machine. Now, you have to push down the green lock lever followed by taking out the cartridge. Further, you have to unpack the new drum unit and place the toner cartridge firmly into the new drum unit. Consecutively, you will hear a sound that signifies that the drum unit is placed properly. Afterward, you have to clean the corona wire inside the drum unit to install the toner cartridge and drum unit assembly back into the machine. With this, the process to install Brother Printer drum comes to an end.
https://www.brother-support.us/install-brother-printer/