CRM Sales Mobile - Change field custom of bp

Hi,
I am a beginner in the world crm sales mobile and I have a problem with the implementation of the method change class CL_MSA_BADI_BUSINESS_PARTNER.
I implemented the method GetDetail (method / MSA / IF_CE_BUSINESS_PARTNER ~ GetDetail) and /msa/if_ce_cust_md~getdetail for the list of values in partner.
as written in the guide and it works fine, but I have implement method change to save any changes.
Can anyone help me?
thanks