Hi @hannit
Thanks for the follow up.
ACF contains a simple function called update_field. You can read about it here:
http://www.advancedcustomfields.com/resources/functions/update_field/
To save the repeater field, you will need to save the $value as a multidimensional array.
The $value will be an array where each piece is another array. This represents each row.
In each row array, you will need to define the sub field values. This can easily be done using the sub_field name as the key, and the sub_field value as the value.
Thanks
E
