Details of how to do it are here, but I will summarise below.
Log into your MCM dashboard via your web browser of choice, and after entering your admin user name and password go to settings (from the top icon bar - the far right hand one after scrolling) and then select firware update from the settings menu on the left hand side (the last entry). From that firmware update menu, select manual update (the lowest entry on the menu, after scrolling down) and point the MCM at the update file using the “Update from file” button.
If that’s what you are following and it’s not working then I would wonder if the firmware file you have is a good one or not - can you give more details of how it fails to update - what errors etc you are getting?
