Forcing a Sky receiver to do a software update is very easy. The process could be terminal for the box if the mains is interrupted in mid-update so please be careful that this cannot happen accidentally.
Here are the steps to trigger an update:
- Switch the box to standby
- Unplug the mains or switch off at the mains socket
- Hold the Back Up button on the box (not the remote) in. Do not release it.
- Switch the mains back on or re-insert the plug
- After a few seconds you should see a black & white screen warning that the box is updating
- Now you can release the Back Up button
After the update the box will reboot and enter standby. Sky+ boxes in particular will take a few minutes to sort themselves out before they can be switched back on. Installers reckon the box can get confused if you try too early.