To change the RESERVE CASH BUFFER after creating your Recycle My Debt scenario:
1. Click on the ACCOUNTS tab (from the left-hand menu)
2. Click on the link at the top of the page (as indicated by the arrow in the below screenshot)
Clicking on the link will take you to the Cash Account details.
At the bottom of the left-hand column of the Cash Account is the Cash Buffer (as indicated in the below screenshot).
Change the Cash Buffer by adding the new buffer amount and clicking UPDATE to save the change.