I'm thinking about buying a new graphic card. What should I do before removing the old one, other than removing proprietary drivers?
I like Oli's answer. :)
The only thing I might add if your paranoid about picking a new card and want to be extra cautious would be to check the Ubuntu hardware catalog for video compatibility with your specific card choice.
Have a cup of tea.
But seriously, that's about all you want to do and you don't even need to do that before you rip it out.
Any old-config issues can be resolved fairly swiftly when the new graphics card is in. If you have issues,
- Get to a terminal any way you can (login if it boots to terminal, or try a TTY via ControlAltF1, or if all else fails, hold shift on reboot and enter the recovery console.
- Remove old driver packages
/etc/X11/xorg.conffrom lower orbit.
These are things you can do before changing but it makes very little difference.