watch os 2 - How to migrate the existing project from WatchOS 2 into WatchOS 3 -

i have existing watchos 2 app. want upgrade , add watchos 3 features, have installed xcode 8 beta 3. question need create target watchos 3 project or can still keep working on same watchos 2 target , add new watchos 3 features there xcode 8.

use same target functions/code need conditional:

#available(watchos 3, *) {     // watchos 3 stuff } #else {     // watchos 2 stuff } #endif