I know the relevant field names are "_dlc_DocId" and "_dlc_DocIdUrl", so at first, I tried to use C# or PowerShell to update the Document ID value with no luck.
Then I reset the Document ID prefix in "Document ID Settings", and ran "Document ID assignment job" manually from Central Admin, Job Definitions page. Still no luck.
After that, I downloaded the file to local hard drive. It's a MS Word file, so I opened it through MS Word, and did find the property "Document ID Value". However it's a read-only property, we cannot modify it directly.
The rest steps are quite simple: remove all document properties, then upload the file to SharePoint to overwrite the previous one.
Below is how I did it in MS WORD 2010.
If the Document ID is not changed, you may need to reset all Document ID of the current site collection.
Then run "Document ID assignment job" for relevant web application manually.