There are two different memory types in your ecu.
1. The flash. Stored on the 29F800BB eprom. 1024kb in size, stores the calibration.
2. The eeprom. Holds adaptations, immobilizer data, and other vehicle specific information. It is stored on the 95040, and is 512 bytes in size.
You need to copy the data from the eeprom in the old ecu. You can do this with Argdubs tool (please read the "Understanding/retrofitting Immobilizer" Sticky in the Cluster and Immobilizer section), with a chipreader and an SOIC-8 testclip, OR just by swapping the physical chip from one ecu to the other.
You may also choose to read the login code from your old, and new ecu, and adapt them using VCDS. Many ways to skin a cat.
Welcome, and good luck