AFAIK if the Freeview box is connected by a fully wired SCART to the TV (and the TV switched on) the as soon as the Freeview box is switched on it will automatically be selected.
There should also be a button marked 'Source' on the TV remote with which you can select various inputs to the TV
The "Source" button may be called "Input" or "AV" or have a symbol composed of a square (representing the TV screen) with an arrow across one edge facing into the square.
As said the SCART should auto switch. Would be worth checking the TV menus as well for anything resembling SCART Control.
Many thanks all, my neighbour had neither the original remote nor manual, the new universal remote he bought was giving out the wrong signals. All now sorted.
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There should also be a button marked 'Source' on the TV remote with which you can select various inputs to the TV
As said the SCART should auto switch. Would be worth checking the TV menus as well for anything resembling SCART Control.