Select the blur you want from the Filters menu. Additional adjustments can be made using sliders in a new dialog box. To blur only the necessary amount of the unwanted texture, start with low numbers and slide to the right .

I've had quie a bit of luck using this software- best $29 I ever spent:
You will lose a bit of detail with this. 


https://scanspeeder.com/

This is a very difficult task to perform.  I assume you are talking about the moire pattern that appears in scans of newspaper copy.  If you attach a sample scan, we may be able to give you some practical suggestions.