Upgrading Macbook HD Question

[Peter Kim]

Hey, just got my 2.0ghz C2D Macbook with 2gb ram and the stock 80gb hd. I've just ordered the HITACHI Travelstar 5K160 and plan on popping it into my Macbook. Ideally I would be able to "clone" my existing hard drive contents so that I can copy it over to the new drive, pop it in and be done. How would I go about doing this? I have an external USB 2.0 enclosure for the 2.5" drive. I noticed someone wrote this in the comments for the hard drive:

"This installed quite easily into my MacBook, and it is a GREAT upgrade for the dollar. If you use OSX, you should buy a cheap 15-25$ external 2.5'' HDD enclosure. With OSX, I was able to put my old 80GB drive in the enclosure after installing the new one. Then you can boot to your old OS in the enclosure. Then you can just use DiskUtility to copy the entirety of the old drive on the new one!! Its a long process for 70GB of data (and it failed on me the first time), but once it finally got over, it was fantastic!"

Can anyone further explain this? It would be very much appreciated, thanks!