It is not possible to rename a sync. What you can do is delete the current sync and create a new one. Deleting the sync does not delete the files being synchronized, so recreating it will not force you to upload your files again.
Rename a Sync
It is not possible to rename a sync. What you can do is delete the current sync and create a new one. Deleting the sync does not delete the files being synchronized, so recreating it will not force you to upload your files again.