You have to copy the save files to your own save data (saves are ID-locked). It don't know, if it work with the save wizard, as you only have the two character saves to choose from.
From my experiencie with it I will explain it:
There are 2 characters saves they should be probably the same is something like redundancy, basicaly you need to repeat the following process twice, one for each character save.
Process:
1. Save YOUR OWN Save from PS to your PenDrive (note that in save wizard you number before the file name, example 45987564charater1.save; this number is your one personal save ID meaning that you cannot use a savefile with a different number in your account therefore you need to use this process)
2. Import the save file that you want from this saveset (it will not be overwritten because it has its own number)
3. go to advance mod in the saveset character1 importted save file. use the button export. choose a location and a name. close advance mod.
4. go to advance in YOUR OWN characters 1 save file. use the button import, choose the exported file you exportted before. close apply and close advance mod.
5. repeat for charater2 save.
note:
you will have 3 other files from your own save, keep them! dont do anything with them.
It will work now!
The only thing that looks like that doesnt work are the throphies such as weapons collectibles and the riddles and the secreet doors, it looks like that the game raises flags and saves it in a different location (or something like that) meaning: whe nyou unlock, for example, the last weapon he basicaly only raises the flag related with that weapon, it doesnt have in memory the remaining weapons.
IF SOMEONE KNOWS HOW TO GOES AROUND THIS IT WOULD BE HELPFULL