I've got a Mac laptop that refuses to update to Catalina via the app store. It starts downloading and just fails along the way somewhere. Presumably in the down

I've got a Mac laptop that refuses to update to Catalina via the app store. It starts downloading and just fails along the way somewhere. Presumably in the downloading stages. I'd suuuure like to be able to download the Catalina installer manually to eliminate network as a dependency. Likewise for all the following incremental updates.