The URL posted by user=DanMc85 downloads fine from a browser.
You didnot explain clearly you used the phone meny to check and you are already on FWV
Once down loaded to your PC,
you can point browser to the IP of your Obi2xxx something like http.//192.168.x.x
On the navigation meny goto System Management / Device Update
At top of page is the Firmware Update section where youy select Browse to brows to the folder and firmware file where you saved it (probably in Downloads on your PC.)
If the firmware is different to what you have it should get downloaded to OBi when you press 'Update' to start the process. Please heed the warning about power supply to stay on, and wait a few minutes so as not to brick the device.