Open the PDF in Adobe Acrobat Pro
Go to File
Select Print
Choose Adobe PDF or Microsoft Print to PDF as the printer
Print the document to a new PDF file
Save the new file
Open the PDF in a PDF editor that supports flattening
Look for Flatten, Optimize, or Print to PDF options
Apply the flattening action
Save the flattened PDF
Use an online PDF flattening tool
Upload the PDF
Select the flatten option
Download the flattened file
Use a command-line tool such as Ghostscript
Run a PDF conversion command to rewrite the file
Save the output as a new flattened PDF
If the PDF contains form fields or annotations, ensure they are included in the print output
Verify the flattened PDF by reopening it and checking that fields and annotations are no longer editable