If for some reason (e.g. when synchronization no longer works properly), you can completely clear and reset OneDrive for Business in a few easy steps.

First, close down all Office programs (such as Word, Excel, Outlook, etc.). Next, open Windows Task Manager, look for and kill these processes:

• MSOSYNC.EXE
• GROOVE.EXE
• MSOUC.EXE

I've noticed that sometimes, these processes get restarted automatically, so be sure they are gone before performing the next step.

Next, locate and delete these folders and their contents:

• %LOCALAPPDATA%\Microsoft\Office\Spw
• %LOCALAPPDATA%\Microsoft\Office\15.0\OfficeFileCache

If needed, also delete the local copy of all synced libraries. The location depends on where you put them the first time 'round.

Finally, start up the OneDrive for Business application, and re-add your libraries.

Note: this was tested with Office 2013.