Gazebo - How to manually input coordinates of objects

Hello, Im using gazebo 2.2 (ubuntu 14 trustly with ROS indigo). I created my world with a TurtleBot robot inside for simulation purposes. Now what I'm looking for is a way to manually input initial coordinates of objects. I want to select an object, for example said Turtlebot (mobile_base) and then place it exactly at X = 1.5, Y = 1.5, Z = 0 and then give it rotation yaw = -1 How do i do it? When i select world object mobile_base it has "pose" property that can be edited but i cant see a way to save these new values, each time i click outisde of the world tab, they reset to previous values.