How to update preprinted material?

Are you the instructor or a student?

Are you the author of the material?

What do you mean by “preprinted”? Do you just mean “printed”?

Scan them in, then use OCR and print them out again after modification. Seems simple enough.

OCR is one of the coolest inventions of the 20th century!

(You do have to proofread very carefully, though. A book I’m reading now had the phrase “in the deli” where “in the dell” was clearly meant and made reference to a “torn cat” instead of a “tom cat”—obvious OCR scan errors.)