To start, you will need to navigate to VAP > Development Maintenance > Development Maintenance. Once here you will need to search for the development of which you need to add these details 

Once you have clicked through the development code, you should navigate to the Plots tab. Once here you should filter the plots using a comma separated list. Once you've filtered these, you should hold down shift on your keyboard and click on the menu top left under details. Finally click the Bulk + Open buttons ensuring that all plots are selected:

This will then prompt you to Open/Save the XML output, choose open and then within the spreadsheet you should be able to add the MPANs/UPRNs within the Plot Notes (AV) column:

Once you have filled in these details, you should be able to re-import these lines into COINS and then navigate to one of the plots of which you have added these details: