How to Convert an Index Created with a Field into Regular Text in Word for Mac

If it's a Bibliography, when Word inserts a Bibliography or Works Cited list, it normally inserts a { BIBLIOGRAPHY } field that is surrounded by a "blue box" labelled "Bibliography". In that case you should be able to click on a little drop-down menu to the right of that label and choose "Convert Bibliography to Static Text"

These blue boxes are called "sdt" s (Structured Data Tags - well in fact, there doesn't seem to be a commonly accepted name for them) and can surround other things such as Content Controls, TOCs (in Mac Word 2016), Citations and perhaps some other things. Each type may have its own drop-down menu.

If what you have is a field then on Mac, selecting it and using command-shift-F9 (or fn-command-shift-F9 depending on your keyboard setup), or command-6/fn-command-6 should "unlink" the field. If it doesn't, some possibilities are:

 - those keystrokes have been assigned to some other command (you can check in Tools->Customise Keyboard..., select the "All Commands" Category, then look for the UnlinkFields command and see what keystrokes have been assigned to it. You can try re-assigning one or both keys and Word should tell you what they are currently assigned to

 - MacOS/Mac OSX is intercepting that keystroke. I suspect there are several possible places you could look for the assignment, but it might be simpler to assign a different key