Do contact support, but the info you need may be here:
I think these instructions will help changed the synced library. Make sure you backup everything first (as I suspect you have already?) http://guides.library.uwa.edu.au/c.php?g=595333&p=4291108 (if your browser will translate from Chinese, you can try this link too! https://support.clarivate.com/Endnote/s/article/EndNote-%E5%A6%82%E4%BD%95%E9%87%8D%E7%BD%AE%E5%90%8…)