PDF Letterhead to Word Template

I have an existing letterhead saved as a PDF and I need it rebuilt as a clean, editable Word 2019 template. The key is that all graphic elements—especially the corner artwork, header, and footer—stay locked in place so the design never shifts when I or anyone else starts typing.

Here is what I expect:
• A .docx file set up for Word 2019
• Standard system fonts only (Arial, Times New Roman, etc.) so nothing breaks on other computers
• Correct margins and section breaks so the header-footer area cannot be accidentally altered, even on additional pages
• No text boxes or objects that float out of alignment when the document grows

Once finished I will drop some sample paragraphs onto two pages; if everything remains perfectly aligned and the branding elements sit exactly where they should, we’re done.