fork oil replacement question

[elcamino12sec]

This may sound stupid but here is my question. In order to replace the fork oil (drain and refill) do I have to disassemble the forks or can hang them up side down with the cap off over night to drain, then replace with new oil. Sorry for the lame question but I have never worked of cartrige forks before. Or if there is a better way I am certainly open to entertain any other method.

 

[Charlie Mix]

On sealed cartridge forks you need to disassemble them and open the cartridges in order to replace "external" and "internal" oil.

If you have older style forks having open cartridges you don't need to disassemble them, but in any case is better if you remove bottom valves in order to clean completely the forks.