Started my ride today and immediately got a loud bang-rattle as the chain came off the rear hub cog and blew out the bottom half of the chaincase. For reference my bike is this style(https://www.emotion-ebikes.de/wp-content/uploads/2020/09/gazelle-citygo-c7-hms-2021.jpg) - my question is, is this a complicated repair that will require the whole back end to be taken apart as when I get a rear puncture, or can it be sorted while the bike is still largely intact? The cog doesn't appear to be damaged/worn and the chain still seems intact from what I can see of it.
I ask because I don't have tools & experience to sort it myself and most bike shops I've tried are reluctant to take ebikes/enclosed drives where they have to take the whole thing apart to fix it, but hauling it out to Corstorphine to Hart's means forking out for a taxi on top of the repair bill.