Open the document to be 'cleaned' in Adobe Acrobat.
Select Advanced > PDF Optimizer
In the PDF Optimizer dialog, select Clean Up.
Ensure that the appropriate boxes for your Clean Up are checked.
Check that the selected Acrobat version in the 'Make compatible with' list is correctly set.
Choose a name under which to save the optimized PDF when prompted and click 'Save'.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.