Hello,
page numbers become part of the page content, so the page numbers tool cannot remove or replace them. Editing existing content is in the works and will be released with one of the upcoming versions once it is finished.
If you still have the PDF from before numbering, the easiest way is to put the pages together there and add the page numbers once.
Otherwise you can remove the old numbers first:
- Open the PDF in https://tools.pdf24.org/en/redact-pdf and choose White as the color of the boxes.
- Drag a box over each wrong page number, only over the number. The content under the boxes is removed permanently when saving.
- Save the PDF and add the page numbers again, online with https://tools.pdf24.org/en/add-page-numbers or in the PDF24 Toolbox with Add page numbers to PDFs.