How to migrate sd card contents on Optimus One?

Hi, I got a new 8gb micro sd card for my phone, to replace my 2gb card. I’ve been looking info about migrating the content of the card, and ive found that in some models its just copying from the card to the computer and then into the new card. But Optimus One cant seem to work, as ive read in several blogs. Maybe with an app? should I format the new card in the phone and then copy from the computer?