You need to unzip the file, it will be unzipped as a folder titled : (namefile), copy this folder to a USB flash drive, create a directory X:\PS3\SAVEDATA\(namefile), put the replay folder there - like this : X:\PS3\SAVEDATA\(namefile)
Insert the USB drive onto the PS3, open PS3 Save Data Utility, copy the replay, it will be shown as GT6 replay 030. Now launch GT6, go to gallery, go to right tab, under filter, pick Load files - open list, it should appear there, and you can view it.