Access ArcGIS Online Item Metadata for Updating

[KansasDASC]

I have ~140 items in our AGO org shared to a Hub app and for each item, the source is listed as the source of user account that owns the items. I want to be able to update the Metadata item to change the item's source to something else. The metadata contact attribute doesn't seem to be something accessed easily under the ArcGIS Metadata standard like Tags, Description, and Summary are. Looking for ideas to update the item's source programmatically. 

I'd think by now you could access all items in the metadata editor with the Metadata class, but can't seem to find more info.

[Laura]

Check out this tool - https://www.arcgis.com/home/item.html?id=3a76c32387324a169c4d8977a3fe3bc0

It let me update multiple sources, tags, etc at once.

[KenNelson]

The Admin Tools will help update tags, description, attribution, but it doesn't it other metadata items like any of the item contact fields.  In this shot, I have two items. Both are shared to the Hub by the same account. The top one pulls the name of the organization from which the item was published. The second item was a manual change in the Metadata Editor to something more specific. This is what we'd like to do as a blanket change. The manual change involves too many button clicks and waiting for things to load. We're at 120 or so items, but other org's have hundreds, so I'm curious to know if there's a better way to change a metadata attribute that isn't a tag, description, title, etc.