If you can print it, you can reprint it. Just make sure that you save a copy digitally when printing (ie: Print to pdf first), and then you can always re-print the pdf. This is also especially useful in case you want to do retro-credit of miles (obviously not the case with Ryanair though), as you dont have to keep printed (used) boarding passes around. Just re-print the PDF again when you want to make a claim.