To sync a Sharepoint Library to your File Explorer:
1) Go to www.office.com and sign in with your ACC credentials.
2) Proceed to OneDrive by clicking on the OneDrive icon.
3) From here you will see your Shared Libraries from Sharepoint on the left hand side of the window:
4) Select the library you wish to sync to your file explorer.
5) Click the Sync button after selecting the library of choice:
5) Chose Sync in the pop-up:
6) At this point your browser will ask you confirm opening OneDrive, it looks different from browser to browser but please accept and allow this popup.
7) Confirm Sharepoint library is now visible in your File Explorer.