Help! I made the horrible mistake of trying to update to Big Sur and now I’m stuck in a failed install cycle. I can’t start safe mode, the screen just goes black and nothing else happens. When I started in recovery mode I found out the problem with the install was that there isn’t enough space for Big Sur, fine, but I can’t stop it trying to install because I can’t get into the computer to get rid of the install file. I tried to revert to a time machine back-up from an external hard drive but even that failed. Is there some way of interrupting the install so I can just get rid of the stupid thing? If not is getting a disc of an earlier operating system and trying to boot from that likely to work? I don’t want to do this as I imagine I would lose all my data...?