By default, certain settings are synced to the servers which makes copying settings between accounts and toons problematic. This behavior can be disabled, the following macro will toggle sync:
/run t = { [0] = "no", [1] = "yes" }; for _, k in pairs({ "synchronizeBindings", "synchronizeChatFrames", "synchronizeMacros" }) do v = 1 - GetCVar(k); SetCVar(k, v); print(k .." = " .. t[v]) end
If you first turn off settings sync, you should be able to copy or edit the settings files in the wow Account folder and they will take effect. These are the relevant files:
chat-cache.txt
bindings-cache.wtf
macros-cache.txt
You may also want to copy the AddOns.txt file which controls which addons are loaded, and the SavedVariables folder(s) which are used for addon configuration.
Edit: removed synchronizeConfig and synchronizeSettings from macro, config-cache.wtf from file list.
Note: I came up with this through googling and experimentation while trying to copy TBC settings into Classic. If your Classic account is already set up properly, you may just want to use the copybara addon to copy chat settings between toons.