Easiest way to reset a Pokemon's EVs in White

[Ekal]

My issue is that I have some Pokemon in White that I am unable to transfer to the newer games (PokeTransfer won't accept them).

I believe that the only reason for this is that there is an issue with their EVs. A decade ago, I may have used some cheat that increased the EVs above the maximum, and now I can't reset them. I have at least a couple hundred of each of the EV-lowering berries. However, no matter how many of them I use on the Pokemon, it keeps saying that the base stat was lowered, and never gets to the point where it says that the stat is as low as it will go. 

I would like to make these Pokemon legal again and be able to transfer them to the newer games. So, I think that to do this I need to reset the EVs. Clearly, the berries aren't going to work, so I figure I need to edit the save somehow. My question is, what would be the easiest and cheapest way to do this? I have a DS Lite, but I don't have a 3DS I can hack (I use a friend's for PokeTransfer). So, I imagine that I will need to either buy a 2DS to hack or get an Action Replay and use that to edit the EVs (if that is even still possible).

Does anyone have any advice on the easiest way for me to do this?