A trick I’m discovering:
Make a google sheet or a Word file.
Insert a table, of three columns.
First column is page number. Second column is “From this . . .” and third column is “To this . . . ”
Make very, very sure that the second and third columns are exactly the same width. Ensure that width is something rather less than your in-page column width in your original document.
Paste the phrase you’re changing in the “From this” column, removing line breaks. Don’t use this method for things that span a paragraph unless you must. If you must, preserve the paragraph breaks.
Make the desired changes in the “To this” box.
If the last word ends in the same place for both From and To, then you probably won’t mess with layout at all.
If it’s shorter or longer, you’ll need to check text flow.
Not sure if this will always work, but it seems right to me.