I concur with post 2.
Download CarbonCopyCloner -- the download is free and you can use it free for 30 days.
Then, use CCC to create a bootable clone of your OLD Macbook on the external HD.
Connect the HD to the NEW Macbook. You now have choices to make:
1. You can use Migration Assistant to "move your files over", or
2. You can migrate files "manually".
Be aware that Migration Assistant will move your entire user account over -- could cause trouble if you have already created a NEW user account on the NEW Macbook.
Also be aware that if you use MA to migrate applications, it's possible that _some_ of your old apps may no longer work with the latest OS on the NEW Macbook.
If you want to migrate things manually, be aware that you CAN copy data files from the individual folders in your home folder (such as "Music", "Movies", etc.), but you CANNOT COPY those folders themselves. To put it another way, you can copy SongA, SongB, etc. from the old Music folder to the new one. But you can't copy the folder named "Music" to your new account.
Once the migrating is done, I would suggest you keep using CCC. However, now you want to create a bootable clone of your NEW Macbook, and keep it around. You ALWAYS want to have a "second, bootable volume" nearby for emergencies.