Make sure both Macs are on the same WiFi network. Fire up /Applications/Utilities/Migration Assistant on either Mac and follow the instructions. It doesn't matter if you're going old to new or new to old. Heck, you can also migrate PC Mac (or rather PC > Mac; I've never tried) Personally I would simply copy files over and start with a clean install. Yes, that means configuring all prefs to your liking, but it's really not that much work.