There are several ways to do this, depending upon what you’re comfortable with. The most direct method is to copy the Music folder from the old 2GB (e250), and using WIndows Explorer (My Computer), transfer this to the new 6GB (e270) one.
Plug in the first Sansa, and open a Windows Explorer window. You can open another window, and select the second (new) e270 in this one, then use copy and paste, or have fun via drag-and-drop.
I like to keep a copy of my music on the hard drive, in case the player needs refreshing. It’s handy to use Windows Media Player, or Media Monkey, so simply load your collection from the original, reatining a copy, then transfer to the new machine.
Let us know a little detail on how you managed your device previously, and we can get you going. The nice thing with the Sansa is that whichever method you use, “all roads lead to Rome”. Quite a bit of flexibility compared with iTunes.