Your 5/03 was using the serial port to communicate with AHMI? Because as far as I know there is no component to communicate through DH+.
If so, and if you were using AHMI and the SerialDF1forSLCMicroCom, then it should be just matter of change each control's com selection after setting up your Ethernet com control. If you have too many visual controls that require this change, try by selecting all those who are the same type (like all the basiclabels) and see in the propierties page if the common controls can be changed.