Bulk Changing Data Source to Portal

[DeanHowell1]

I have published a large number of layers ( > 200) from a project in ArcGIS Pro into the Data Store in Portal for ArcGIS but want to see if there is a way to update the project in a quick and easy way so the project now points to the layers in Portal for ArcGIS?

I know I can change the source one by one by right clicking on the item but this will be very time consuming for 200 layers. 

Any ideas?

Thanks

Dean

[Natalie_Runyan]

my variation on this question is to change data sources in an MXD from AGOL layers to same layers from our internal Portal. I'm thinking there should be a way to include services in the list of sources shown in the 'update data source' option in Catalog.