In the application view, click the Documents tab .
In the table pane, select the document that you have previously checked out and edited and are ready to check in.
In the Documents application view action bar,
click 
.
In the File Check In dialog box, select the language of the file content from the drop-down menu. You should change the language only if you have changed the language of the document.
As an optional step, you can type comments to describe the changes that you made in the file. These comments are displayed in the notification e-mail and can be helpful to those who receive the notification
Click Browse to navigate to the location of the file. Double-click the file name to enter its full path into the File dialog box.
Select Keep checked out if you want to keep the file you just uploaded checked out. Keeping the document checked out means the document will still be unavailable for check out to other users.
Click Upload.