Hep - Adjusting customer accounts

Help

One register store using RMS.

Trying to clean up an RMS system that has a 40 or more user account with old account receivables amounts that were done years ago. How can I adjust the outstanding balance back to zero - without affecting any amounts on the x-reports or z-reports.  I see that you make adjustment by doing:

1. In the Customer Properties window, click the Account Information tab.

2. Select the applicable invoice, and then click Adjust.

3. In the Adjust Customer Account window, modify the appropriate information, and then click OK. 

What those this affect in the RMS system.  Please advise.

Thanks

Danny