Usually yes, using the same web interface method. However, downgrading can reintroduce security flaws. Only downgrade if the new firmware causes hardware issues (e.g., overheating or frequent reboots).
The IB-WRB304N firmware update process is functional but high-risk due to poor manufacturer support. Only proceed if you have the exact firmware file matched to your hardware revision and are prepared to unbrick the device via TFTP. ib-wrb304n firmware update