You can access the Comparison Tool from the following locations:
From the Document Toolbox
Navigate to a page in the document.
Click Document Toolbox.
Click View changes underneath the document title.
From the Document Manager
From the Document Library, click the actions menu ••• on a document and select Manage.
From a page in a document, click Document toolbox and select Manage.
Navigate to the Comparison Tool
Click Versions in the space sidebar.
For the version you want to export, click Compare.
In the Comparison Tool, select the version with which you want to compare.
Scroll through the result to view the changes or use Previous and Next in the bottom action bar to navigate between the changes.