How to remove all watermarks on all pages of a pdf file?

[mattad]

Assume I got a pdf with watermarks on (almost) all pages of a pdf file.

How can I remove the with only a few clicks (=not by selecting each pattern and remove it manually)?

Similar, related, opposite question:

Assume I have a pdf file with NO watermark and an external (*.png) file which contains just a light grey watermark picture.

How can I set this watermark picture as (centralized) watermark on all pages of the pdf?

Matt

[Ovg]

How can I remove the with only a few clicks (=not by selecting each pattern and remove it manually)?

Organize->Watermarks->Remove All - Ribbon UI
Document->Watermarks->Remove All - Classic UI

Assume I have a pdf file with NO watermark and an external (*.png) file which contains just a light grey watermark picture.
How can I set this watermark picture as (centralized) watermark on all pages of the pdf?
Matt

Organize->Watermarks->Add - Ribbon UI
Document->Watermarks->Add - Classic UI

[TrackerSupp-Daniel]

Thanks OVG, you beat me to it!
Have a great day guys!