Hi

I created a form in Word a few years ago now which is saved to a SharePoint document library once completed.

There are some required fields in the document properties which need to be completed before it will allow saving, I need to edit the content of the drop downs and I can't remember how I set these these and where they can be edited.

They don't appear in the Advanced Document Properties tab, anyone able to guide me in the right direction?

This is apparently a SharePoint problem.
You could look under Insert > Quick Parts > Document Properties. They may be there. You may have to insert them into your document to modify them. (I do not use SharePoint so am guessing.)
Backgroundf: Enhanced Document Properties AddIn and XML location of Document Properties in Quick Parts list - Expand / modify that list.

When a Sharepoint Library has been created with a custom document type, it adds metadata to the documents that are save into that library. If some of those fields are set to 'required' then they become compulsory fields that require a value when loading a document to that library. If your Word form was previously saved into that Sharepoint Library, then it will already contain the required Sharepoint fields and you can edit the contents of those fields prior to loading the document to Sharepoint.

To edit these fields via the Word GUI you can insert a linked Content Control onto the page and edit the value which writes back to the metadata field. The Content control can also be removed/deleted from the document without changing the value stored in the metadata. To get one of these linked CCs, you can use Charles' suggestion of Insert > Quick Parts > Document Properties
Alternatively, if you are showing your Developer Tab, you can go to Developer > XML Mapping and find the relevant xml file and field then right click it to insert the CC as a Plain Text Content Control into your document.

__________________
Andrew Lockton
Chrysalis Design, Melbourne Australia