Steps to Send sales Order Custom field from CRM to ECC

Hello All,

I have created custom field in Customer_I table using AET. Similarly I have custom field in ECC in VBAP.

Now I want to replicate these custom field from CRM to ECC using CRM_DATAEXCHG_BADI and method -  CRM_DATAEXCHG_AFTER_BAPI_FILL.

Can anyone please help me with the exact steps to achieve the same? and sample code of how to populate table - CT_BAPIPAREX within this method? 

Thanks in Advance.