I geleich after unpacking the computer the existing 4GB 2-bolt removed and fitted all 4 banks with the 8-bars from Corsair. The procedure is almost impossible to simplify - a no brainer.
The iMac drove impeccably high, pointed to the establishment of his right to 32GB and announced in systems analysis, that he was completely satisfied with these bars. He remained in the coming days, he runs around.
A fairly easy way to its iMac configure a bit cheaper; who ordered the storage extensions for Apple, is really own fault.