• Type enough of "bluetooth file exchange" to find the Bluetooth File Exchange app and launch it.
• Bluetooth File Exchange will see that Bluetooth is off and give you a dialog offering to turn it on, with turning it on the default action, so just hit return and Bluetooth will get turned on.
• Hit ⌘-space to open Spotlight.
• Type enough of "bluetooth file exchange" to find the Bluetooth File Exchange app and launch it.
• Bluetooth File Exchange will see that Bluetooth is off and give you a dialog offering to turn it on, with turning it on the default action, so just hit return and Bluetooth will get turned on.