Jeep Liberty Differential Axle Replace/Remove

The Vehicle Is Due For A Tune Up, And One Thing On The List Is To Replace These Fluids With Synthetic Fluid, But I Do Not Know How To Do...

How Do You Replace The Fluid In My Front And Rear Axle? Is That The Same As A Differential Axle? Also, What Is A Transfer Case And How Do...

Can I Put A Rear Axle From An '03 2 Wheel Drive With Drum Brakes In My 4x4 With Disc Brakes? I Don't Think I Have Anti-lock. Mark