There is a neat technique called ”stripping in” that lets you cut a word out of the page and replace it with the corrected word from another page. You can use it to correct a misspelling if the length of the corrected word is the same as the wrong one; it avoids having to reset the whole page.

You put the page with the correct word underneath the copy, on a light table (a real one). With an exacto knife, carefully cut out the word, cutting through both sheets. Now the correct word fits exactly in the hole. Hold it together with a piece of white tape (standard supply in all these shops) on the back. The mend is invisible.