The guides may be good, but they're not up to date, it's definitely possible on a 3DS, you just have to enter the game 8 seconds before the desired time.
Omega and I have made it a policy not to use .pkm files as they can potentially lead to problems regarding the loss of legitimacy of the pokémon themselves. It can be read on the thread itself. Let me see if I can work something out to make the process faster.
Oh, I don't really like handling .pkm files, so we'll be trading the old-fashioned way (BTW, do you want nicknames on any of them?). The guide you see there is all you need to start breeding and catching, and bearsfan put up a VERY useful video guide on Youtube that you should definitely watch.