Restrict printing or changes to a document

With the PDF document open, choose Document > Secure > Show Security Settings For This Document.

Choose Password Security from the Security Method menu.

From the Compatibility menu, choose the earliest version of Acrobat that you want to be able to open this document.

Select the check box under Permissions, and then type a Permissions password. This password is not required to open the document, but only to change the security settings. It must be different than the Document Open password, if one exists.

Choose which printing and editing changes are allowed.

Click OK, type the Permissions password again, and then click OK.