As a writer there are few things more annoying than finding out your work needs to be re-sized. Usually this happens because one of the printers you requested a quote from responds with a quote for a different size which is dramatically cheaper than what everybody else quoted for the size you had originally chosen. This can also happen if you are using POD services because they don’t always print “standard” book sizes.
We will assume you have joined the modern world and are running a Linux desktop instead of some obsolete Windows platform (doesn’t matter what version, they are all obsolete) or that BSD distro with a different GUI called MAC OS. We will also assume you didn’t spend money on a commercial product like Master PDF Editor so you could resize the page while centering the existing content. We will also assume you are going bigger, not smaller. I have never tried this with smaller. If you aren’t using a Debian based distro heaven help ya . . . I mean . . . you will need to tweak the following install command for your environment.
sudo apt install texlive-extra-utils
Once the installation completes you can cd off to where ever your source PDF is and execute the following changing the output and input file names accordingly:
pdfjam --outfile logic_book_7x10.pdf --papersize'{7in, 10in}' logic_book.pdf
If you were foolish enough to put spaces in your file name you will need to enclose the entire filename in single quotes. In the case of that book I was moving from 7×9 to 7×10 and the results were fine. I didn’t try anything drastic, but please feel free to experiment.