I think you are referring to the Touch Up Reading Order tool. You will find it in the Tools pane under Accessibility. If the Accessibility tools are hiding you can make them visible by View > Tools > Accessibility. But ... it will not be of help in removing a watermark. It is used to add and modify accessibility tags. To remove the watermark - first make sure you work with a copy of your document, since things can go horribly wrong using Acrobat. You could try selecting and deleting the watermark using the Edit Text & Images tool (under Content Editing) or the handy but deprecated Edit Object tool (under Print Production), or find it and deleted in the Content pane. If none of these work, you could try posting in the Creating, Editing, & Exporting PDFs forum - lots of knowledgeable helpful visitors there.
i had heard fro the touchup tool which is under print production in acrobat X.conetnt pane?