If an EEPROM location is "worn out" what it means is that particular location may not store the data you have written to correctly. If you are still able to read the correct data after your write to it (E.g. write a &HAAAA to it and read back, then write a &H5555 to it and read back to check) then it is probably still OK.
The earlier PLC models (before 2002) the EEPROM life cycle is about 100,000. The later model could withstand at least 1 million erase/write cycle.
If you are concerned with the effect of the past write cycles exceeding its life cycle and could impact future operation, you can change the location you are writing to, or simply replace it with the standard EEPROM (M2017P) or the expanded EEPROM (M2018P).