What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I'm sorry, I'm quite confused on what you would like to do. If you would like to allow your users to upload files on the form, then you can do that by following this guide: https://www.jotform.com/help/332-How-to-Create-Upload-Forms.
If you want to change the max file size limit, you can do that by checking this guide: https://www.jotform.com/help/33-Changing-the-upload-size-limit
You can also enable the "Allow Multiple" option in your file upload field:
With that option, your users can easily remove the previously selected file in the upload field:
I hope that helps.