Help to change file names of ≈:1000 documents

We have an online portal of 2360 documents that have been renamed and are looking for a temp to update the dates on all documents. We have downloaded the names of all files into an Excel sheet. Once we kick off the project, we will give you access to the portal where documents are saved. Some documents already have the date in the old naming system. In these cases you can just paste the date into the new name.