There are some very good online services around which will allow you to manipulate PDF files, or convert non-PDF files into PDF format. My latest discovery is SmallPDF. It offers a whole host of features. You can convert a document or an image file to PDF, for example, and you can even split, merge and rotate PDF files. If you've downloaded a PDF file which is locked to prohibit you from editing or printing the file, you can even remove that protection. A subscription to SmallPDF costs $6 per month, but is free if you use it no more than twice per hour.