File -> Open, select to highlight the drawing you want to change.
click -> References button
This next part is a bit tricky; higlight the name of the file you want to replace, now double click the name while it is highlighted.
Select replacement file, click OK, click OK, Click open.
Nice!...Thank you Troy!
File Open, References! Also not in the help info.
Good lead to my solution. Thank youTroy.
Usually I could hide the old model for the copied drawing, then Inventor would politely ask for the missing model on drawing open. You could tell the drawing the new model filename to use.
Edit: Dismissed Messages can hide the need to locate the missing model.
Thanks, Glenn, for the reminder of SWK Explorer usefulness (below).
There is another way to do this that I prefer. Find the drawing in SW Explorer, click on it to highlight it, go to the References tab, RMB on the file you want to replace, and choose Replace. Then browse to the new file.