1) Go with your opencompas URL then you will get the login page, after that you have entered your ID and PASSWORD
2) After that you can see the dashboard then click on the Fee module
3) As you can see menus, just do a mouseover on Voucher then click on the Voucher entry
4) Now you have to enter the Admission number or Select a course and search by name for see fee detail after that you will see the adjusted amount on the left side which is highlighted by red color as shown below image
5) Then you need to adjust this amount, for this go to the Transaction menu and Fee Head Auto Adjust 
6) Now as you can see below image there is two option Admission number wise or Course wise select anyone that you want and click on the Show button. 
7) After that you will see a table with some details of student now you need to click on the Adjust Voucher
8) As you can see below image not adjusted amount is displaying on the left side. In the right-side detail of the fee, the head is displaying select(check inbox) anyone fee head that you want to adjust that amount after that click on the adjust button.