Well Thanks to an update a few month’s back it’s now extremely simple to do so:

Browse to:

https://companyname-admin.sharepoint.com/_layouts/15/online/TenantSettings.aspx

Scroll down to the bottom of your page  Save your changes and you are done

You can also remove Onedrive sync fuctionality from a Document library or another app.

Go to the sitesettings of the library you are in.

Select Search and offline availability. And change the Download to offline clients to NO.