Which specific reference type did you use for the record for this this citation and do you use that reference type for any other citations that would require the “retrieved” rather than “adapted” wording in the bibliography?
If not, then you just need to edit the output style replacing the word retrieved with adapted for that reference type template in the bibliography section of the output style. - edit the output style via Edit>output style> edit “APA 6th”, go to the Bibliography>tempaltes section and find the reference type, and edit the wording, leaving all the other surrounding characters in place. Then SAVE AS to a new name, and in the word document change the output style to the new name.