Instructions on what was done:
You need 2 people person A and Person B. The goal is to get certain pokemon to person B without losing them on A. To complete this you need to backup your saves. There are two ways of backing up saves, on the R4DS you can backup a save by going into the directory with the game you wish to backup, and hitting select until you see the . SAV file and push A on it to back it up. Another way is to put your microsd card into your computer and go to the directory and copy the .sav file to the desktop or some folder. Now here is what is done:
Step 1 exchange friend codes.
Step 2 Both people SAVE and make BACKUPS.
Step 3 connect on Wi-Fi.
Only one person needs
Now here is where it can get tricky depending on what is being done. If there is one pokemon to be traded and that is all (no need to trade back it would go as follows (this was the Knab case)
Step 4: Person A sends whatever to Person B.
Step 5: Disconnect, and Person A reverts to old save file where he/she had the pokemon that were sent. This is accomplished by copying the save file back, or hitting A on the .BAK file if you made backup on R4DS.
Both Need
If the pokemon is needed by both parties it is done differently. This was how it was done when we were trading starters.
Step 4: Person A sends Person B a pokemon.
Step 5: Both disconnect. Person A proceeds to use his or her backup save found on the computer or the ds. Person B saves and makes a new backup on his or her computer or ds.
Step 6: Reconnect online. This time Person B sends the Pokemon A wants to him.
Step 7: Both disconnect. And Person B will revert to the save that was made in step 5 where he or she had both pokemon they wanted.
I hope this helps sort out the process of manipulating the .sav files over Wi-fi. Of course itèll be easier once AR codes are out, and if you can Hex edit.