Article in English: It's a green app with a white "X" on it. To open a shared document that you wish to unshare, you'll need to load the document from OneDrive. You should see it on the left-hand side of the page. If you've recently opened the document, it will appear on the left side of the page; simply click the version of the document that has "OneDrive" written below it. It's a save location on this page. Doing so will open it in Excel. You may need to click through some folders to navigate to it first depending on where in OneDrive the file is stored. If the name of the document at the top of the Excel window has "[Shared]" to the right of it, it is currently being shared. It's on the far-right side of the Excel toolbar that's near the top of the page. Doing so will invoke a drop-down menu. This process will remove your selected user from the document's sharing list. You'll repeat this process for each user in this section. It's an option in the toolbar at the top of the Excel window. This option is in the "Changes" section of the Review tab. This box is next to the "Allow changes by more than one user at the same time" section. Doing so will completely unshare your document and remove any users not manually removed by you.

Summary in Indonesian:
Buka Excel. Klik Open Other Workbooks. Klik OneDrive. Klik dokumen yang ingin dihentikan pembagiannya. Pastikan dokumen bersama sudah terbuka. Klik label Share. Klik kanan pada salah satu pengguna. Klik Remove User. Klik label Review. Klik Share Workbook. Hapuskan centang pada kotak di bagian atas jendela. Klik OK.