Dear Mods and members,
I have a very old laptop of 2006 which is still in prestine condition and runs best in Knoppix 6.2.1. Later versions slow it down.

Of late I realised that I need to update the /etc/apt/sources.list to include certain packages. However, Debian Lenny has since moved to Archive. I would need to change the sources.list entries. Lenny archive is straightforward. Security info and line is bit complicated, I can't implement it.
Please advise.
Regards