Change space with mouse wheel + modifiers
If you use the Apple Magic Mouse you can change between spaces by "Swipe left or right with two fingers".

You should check if you have active this option on System Preferences → Mouse → More Gestures.

Additionally, if you want to change it with only one hand, you could change the shortcut for "Move left a space" and "Move right a space" under System Preferences → Keyboard → Shortcuts → Mission Control to something easily usable with a single hand like ⇧+ctrl+z and ⇧+ctrl+x