I would like to know what to do to change the security settings of a document when I forgot the password

[YolandeH]

Acrobat DC need the password to permit that I modify the security settings

[Test Screen Name · Accepted solution]

Yes. Remake the file.

[NMukundan]

How do I remake a file? Please help with the steps to remove the password from the document.

[frazzlesnap]

Reset the file from scratch in the original application, or find a program to open the pdf that doesn't apply Adobe's security standards to bypass the password requirement.

[Abambo · Accepted solution]

How do I remake a file? Please help with the steps to remove the password from the document.

By @NMukundan

You will need the source file (Word, Excel, InDesign, … , whatever application created the PDF file). You export again to PDF.