djgrits7
Here's another solution.
Since you have disk utility opened up, let's do this:
In the disk utility window, select and highlight your 250 gig drive.
Then hit the new image tab in the menu bar of disk utility. A window will open. Give it a name and select the 350gig hard drive as the location.
That will create the disk image of your 250 gig drive to your external drive. It will not erase your music from it.
Verify that the image is created and stored there.
From that point, you can replace your hard drive with the new.
After the drive is replaced, start up from the CD again and open disk utility again. Name the new drive and make sure the format is correct.
Then click the restore tab, click on the image button to the right of the source and select the disk image of the old drive from the external.Then drag the new drive to the destination field to populate it. Then click the restore button at the bottom of the window.
Once complete, select the new drive with disk utility and repair permissions. Also, verify the new drive is OK.
After all is complete, go the system preferences and select the new drive as the startup.
All your info will be on the new drive and since it won't be full, you should be able to select it and startup from it.