To remove the old libraries in the bottom right hand corner of your desktop near your clock, right click on the SharePoint icon and select “Stop syncing folders”, select the folder location you want to stop syncing and click “Stop syncing”

To add your new locations please follow the below;


Sign into Office 365 and click the  in the top left and select sites 

Depending on the site you require to sync, click on them to take you to the SharePoint site and click the sync button circled in red below


This will open a new box in the same tab asking you to confirm you wish to sync