[Theme ArcadeBasic] Revert to previous version

I’ve been in the mist of renovating my wordpress site and saw that my theme had an update. After updating, I no longer have the option of giving my pages the full width and am forced to give it a column. I’m trying to revert to a previous version of the theme but keep receiving an error that certain files are already in place. I don’t want to switch themes only to have the work I’ve put forth thus far erased. Any help would be greatly appreciated. Thank you in advance!