Updating the MikroTik firmware is easy enough, just open the web-interface of the device or WinBox, select “System” – “Packages” from the menu and click “Check For Updates”, if a new firmware is found, then click “Download & Upgrade”. The device will download the firmware from the official website and starts from it.
To flash MikroTik devices not to the newest version, or when the device does not have access to the Internet, I propose the following:
1) Download the firmware from the official website
2) Connect via WinBox (not through the web interface!), Select “Files” in the menu, a window will appear, just drag the firmware file with the *.npk extension and wait for the file to upload.
3) Reload the router. It will have to start with a new firmware.
To downgrade the firmware version, you need to perform steps 1 and 2, then connect to the device via telnet and run the command:
/system package downgrade
In case of problems, you can restore the router by following the instructions Restoring MikroTik (RouterOS) using NetInstall