Hi, make first the backup of original sd-card, then paste the new data.
The old (poi) and phoneme (ph) can be completely replaced with new data.
The old map (fbl) must be renamed for example as "xxx_old.fbl" (Not delete this fbl) and then new map simply placed in the same map folder.
Ready, that's it.
Put the sd card in navigation...this will complain about "not accepted" after that press ok.
So, the new map on the card now works.
Best regards.
(it was translated with Google-Translate