The following are the steps I take update Debian by making a fresh install on a clean drive.
Create a drive. There's plenty around to explain this step if you're not sure.
Format and mount the drive.
mkfs.ext4 /dev/sdb1 #enter your drive here
mount /dev/sdb1 /mnt
Install deboostrap and bootstrap the system using your arch and preferred distrobution. Mount proc and dev.