How do I replace an upload?

I'm not sure I understood your question correctly. Do you want to replace your upload field?

Can you please explain further how your form flow works? Do you want to upload a file?

Looking forward for your response.

After someone has completed/submitted my form which required an upload of their document, is there a way for either me or the person that uploaded it to begin with to update? For example https://www.jotform.com/uploads/sruble/80233988790973/4301123385312009047/1903%20PRM%20implementation%20research.pdf. Is there a way to amend this document?

Yes, that is possible. You can send them the edit link for their submission or if submission editing is enabled on the autoresponder then they can access the edit submission there.

Related Guide: How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date

If you want to manually grab the edit link for each submission, please get the submission ID and form a URL like this: https://www.jotform.com/edit/submissionIDhere

Guide: Where-to-Find-the-Submission-ID