Updating pdf file
If your hosting service does not allow you to have PDF files on your website, you can get your own domain name for your website or switch to another hosting service that does allow PDF files or large files on websites.
Adobe Acrobat Reader DC software is the free global standard for reliably viewing, printing, and commenting on PDF documents.
For example: If you are creating your website on your computer, before downloading the PDF file to your server, test the link to the PDF file to make sure it works properly.
(Edit 6/14/13: CS 6 allows you to create your form fields directly in In Design, so this finally resolves the need for cumbersome workflows such as the one described below.
But then do you have to re-create all the form fields? You don’t even have to copy the interactive elements over to the new file. Now, go to Acrobat Pro and open your old PDF containing the interactive elements that needs to be updated with this new content.
The best way to do this is to import the new PDF pages into your existing PDF form using the Replace Pages option. Feel free to open up your source document in MS Word, In Design, or whatever application you’re using, edit it, and export your new PDF (but don’t overwrite your form! Open the pages panel (usually on the left side of the screen), right-click on the page(s) you want to replace, and choose “Replace Pages.” Select the appropriate page range from the dialog and choose OK.
By clicking the "Download now" button, you agree (a) to the Adobe Software Licensing Agreement, (b) that you are installing an application designed to view, print and annotate PDF documents, and (c) to the automatic installation of updates to Adobe Acrobat Reader DC.