You can make changes to PDF files as long as you have the full version of the Adobe Acrobat software. If you only have the Adobe Reader, you will not have editing capabilities for PDF files. Although a PDF is usually only used for viewing a completed document, there are times when revisions must be made to the PDF file.
Edit text in PDF files by using the Edit Document Text tool. Click "Tools," "Content," "Edit Document Text," which is found under the Add/Edit Text option in the sub-menu. Select the text you want to edit and apply your desired property changes, such as font color, font size, character spacing and word spacing.
Add new text to your PDF by selecting your "Edit Document Text" tool, pressing your "CTRL" or "Option" key and clicking your mouse where you'd like to add your text. Select your font from the New Text Font dialog box that opens and type the text you want to add in the text field box that appears. Click on "Properties" and check "Embedding" and "Subsetting" to embed your new text into the PDF document.
Click on the "Pages" panel to add pages, reorganize pages or delete pages. To add pages from another PDF file, open both files and split your screen. Click on the "Pages" panel in the document you want to add the pages from the other document to. Grab the pages from the other document and drag them over into the Pages panel. Release them once you've placed your cursor where you want the new pages to appear. Reorganize your pages by grabbing each page in the "Pages" panel and moving it to where you want it to appear in the PDF file. Delete pages by highlighting them in the "Pages" panel and hitting the "Delete" key on your keyboard.