Você pode usar o Gparted para realizar sua tarefa.
Certifique-se de fazer isso a partir de um CD ao vivo, para garantir que as unidades sejam desmontadas.
This article shows how you can modify the partitioning of your Linux system with GParted (Gnome Partition Editor) without losing data. This includes resizing partitions (enlarging and shrinking), moving partitions on the hard drive, creating and deleting partitions, and even modifying filesystem types. GParted is a free partition editor available as a desktop program and also as a Live-CD. It supports the following filesystems: ext2, ext3, fat16, fat32, hfs, hfs+, jfs, linux-swap, reiserfs, reiser4, ufs, xfs, and even ntfs (Windows). Have alook at this
Fonte: howtoforge
NOTA: Ao lidar com partições, certifique-se sempre de que um backup esteja disponível, caso algo dê errado. Você pode considerar o Clonezilla