This is how I go back to the old Particle System :-

Start off.

In Hierarchy , Create > Particle System (yes, this is the new one, hang on ...)

Now from the main window options, select :

Component > Effects > Legacy Particles > Ellipsoid Particle Emitter

next , add the component :

Component > Effects > Legacy Particles > Particle Animator

next , add the component :

Component > Effects > Legacy Particles > Particle Renderer

Now , to remove the new particle system.

In Hierarchy , click on the Particle System. All the components should now be :

• Transform
• Particle System
• Ellipsoid Particle Emitter
• Particle Animator
• Particle Renderer

Right-Click on the Particle System Component , then select Remove Component.

Now your particle system should be set up like the old Ellipsoid Particle Emitter system :

• Transform
• Ellipsoid Particle Emitter
• Particle Animator
• Particle Renderer

just change the material in 'Particle Renderer - Materials' to the original Default-Particle , or your own star !

now you should be able to follow the tutorial.

Hope this helps =]