delete or merge duplicate record in detail via business process

Hi everyone!

I am stuck with the BP, hope you can help me out.

I have a detail with duplicate records in it. These records are automaticaly added after the certain emailing (via webhooks). The issues is there are duplicates and I do need them - I need some of them be deleted and at least one should be staying (see image below). 

I cannot understand how to write the deleting part in business process