There are a couple of techniques, the simplest is to use a chrooted environment. In this environment you can then run
sudo aptitude update and most other command line tools.
Alternatively you could create a number of virtual box virtual machines that used the partitions as their hard drives - I have not tried this.
For the chroot environment
mount each partition in a directory for example:
sudo mkdir /mnt/partition_penguin
sudo mount /dev/sda8 /mnt/partition_penguin
Bind in the system directories to give access to the hardware:
sudo mount --bind /dev /mnt/partition_penguin/dev
sudo mount --bind /proc /mnt/partition_penguin/proc
sudo mount --bind /sys /mnt/partition_penguin/sys
And then enter the chroot environment and run your commands:
sudo chroot /mnt/partition_penguin /bin/bash
sudo aptitude update