This is a astable circuit, which means it has two semi-stable states, with either one or the other transistor been turned ON, and the other being turned OFF. When the LED is lit, then the current is basically that off the current through the LED (set by it's series resistor), when it's OFF, then the other transistor is turned ON, and the current is set by it's collector resistor. So to reduce the current you can increase the value of that collector resistor - but it will have some effect on the timing, and if increased too far will stop working all together.
You can alter the ON/OFF ration by changing the capacitor values, or the base resistor values - probably simplest for you to alter the capacitor, unequal values will give an unequal flashing ratio.
Try different values and see what happens! - it's a good learning experience!.