If you have Adobe Acrobat, then yes – it first depends on whether the pages of text are “images” (if you click somewhere on the page, does the whole page get selected?) or whether words are recognized as words.
If they are recognized as words, go to Tools > Advanced Editing > Text TouchUp Text Tool. Using this tool, if you click on the text that you want to edit it should (after a pause) show you the boundaries of the block of text and allow you to edit the text.
If words are not recognized, and each page is an image, then you’ll first have to go to Document > OCR Text Recognition > Recognize Text Using OCR. This will turn your image into recognizable, searchable words. It doesn’t always work perfectly, particularly if you have a bad scan or if there are actual images embedded in your page. After the OCR process, you should be able to edit the text as I described above.
A warning, though – editing in Acrobat is a pain in the ass, and you should budget time to experiment a bit and see what effects your changes have on the page as you go. And save a backup copy of the original in case you screw it up badly.
But the only way you could be “stuck with what you’ve got” as @Lightlyseared said above, is if the file is locked for editing. Otherwise, you should certainly be able to do something with it, particularly if you are only doing minor changes.