Hi ,
Go to respective data source(Ex red in my pic)-->right click, manage, there you will see 3 request which are green. click on QM status(green, blue color in pic), next pop up, choose radio buttion which indicates red. like that do for another req which you want make red. now your psa have 1 and 3 as red status at psa.
Now trigger dtp, 2 req will move to target. later come back same screen, data source--> right click manage, make red request to green again.
Thanks