Help Motorola Milestone sd card help

[goingbeastmode]

Hello, I have been meaning to join this forum for awhile now. I have the Motorola Milestone 2 and I just downloaded MybackupPRO to backup everything on my phone exept the music. I have tons of music , so my plan is to buy a bigger sd card (2 gb is whats in phone now)
to store only my music on the card. Everything else on my phone is backed on mybackupPRO, so how can I do this?

Thanks alot