Place the folder containing your 100% save data into that directory.
: Make sure the save file's Region ID (e.g., ULUS for USA, ULES for Europe) matches your game's region, or it won't load. MotoGP Save Game Files for PSP - GameFAQs - GameSpot Save Data Motogp Psp--
The most reliable method for backing up data is connecting the Memory Stick to a Place the folder containing your 100% save data