It can be really useful to edit scenes names with a texteditor rather than in Ableton interface. A good subject on how to edit Ableton projects at : https://forum.ableton.com/viewtopic.php?t=121089&start=15

You can decompress the .als file with 7zip for example. Then the file is a basic xml file

You can find scenes names in a dedicated section in the xml file :

		<SceneNames>
			<Scene Id="9" Value="Intro;100 BPM ">
				<Annotation Value="" />
				<ColorIndex Value="0" />
				<LomId Value="0" />
				<ClipSlotsListWrapper LomId="0" />
			</Scene>
			<Scene Id="10" Value="Compo 1 100bpm">
				<Annotation Value="" />
				<ColorIndex Value="0" />
				<LomId Value="0" />
				<ClipSlotsListWrapper LomId="0" />
			</Scene>
			<Scene Id="48" Value="Compo 5 127bpm">
				<Annotation Value="" />
				<ColorIndex Value="0" />
				<LomId Value="0" />
				<ClipSlotsListWrapper LomId="0" />
			</Scene>

You can then compress the file again in a .als format with 7zip in a "gzip" format like this :