I agree with those who say just do it - without first consulting the FAs. Think of it this way: if you ask and they say "no", then you look like a complete a-hole if you try the switch anyway. If you DON'T ask and then the FA tries to prevent your switch, SHE/HE looks like a complete a-hole for not letting you make an innocuous change. The above are worst-case-scenarios; if the FAs are like 90% of the other FAs on CO, nobody would mind - regardless of whether you ask.

In short, its easier to ask for forgiveness than to ask for permission.