Remastersys, é uma ferramenta gratuita para isso você pode instalá-lo via ppa
Você pode encontrar mais informações aqui fórum remastersys
Instruções de instalação citadas no fórum remastersys.
The Synaptic Method:
In Firefox, go to:
http://www.remastersys.com/ubuntu/remastersys.gpg.key save file as text someplace where you can find it.
In synaptic, go to Settings/Repositories; select "Authentication" tab and "Import Key File" just downloaded.
Still in synaptic, go to "Other Software" tab and click "Add", then enter the apt line and replace oneiric with either lucid, maverick, or natty to match your Ubuntu version:
deb http://www.remastersys.com/ubuntu oneiric main
Leave the repositories tab and "Reload".
Search for "remastersys" and select for install. Edit/Apply Marked Changes.
The Manual Method
Download and apply the repository signing key.
wget -O - http://www.remastersys.com/ubuntu/remastersys.gpg.key | sudo apt-key add -
Add the following line to your /etc/apt/sources.list, substituting "oneiric" for your Ubuntu version (e.g. lucid, natty, maverick)
deb http://www.remastersys.com/ubuntu oneiric main
Now just
sudo apt-get update
or reload in Synaptic to have the new Remastersys signed repository ready to use!