Changing each table connection string within dataset published on server

Hi Guys,

i have 2 tables in my dataset. 
One is coming from REST API (WEB URL source) and second one is coming from postgresql ado connection string. 

I logged into Power BI Server (i have PPU license) and seeing screen:

How can i change each connection string for each table? 
What i am thinking is to add parameter for each table name like web Url string + tableName 
And postgres ado connection string + tableName .

But i can not imagine how this should be done exactly.
Imagine i have 2 different tables with the same url beginning, like "https://myendpoint:9999//table1" and "https://myendpoint:9999//table2". How to change only first part of url and keep tables there? 
Or how to delete whole dataset and add different tables from different sources? 

What steps should be done?
1) add parameters for each connection string for each table (it required to do manual work for each table which i do not want to do) 
2) get lists of all parameters via powershell for example and change them? 

Please help,
Best,
Jacek