how to use .add.class.remove.move?

how to use .add.class.remove.move?

I want to know how to use .add.class and .remove.class im confusing and .css not work.

I just did .css and work but when i combine with other function it is not.
1. I want to add $('img a') float to right, margin left and right, (i know it)
2. then move the $('p.mobile-photo') to other div (not append or prepend, i mean inside the div 'separator' class) i don't know this script
3. then remove the <p class> after all i want to move the separator class to the top of desc class (i use before but not work)

only know .css

http://jsfiddle.net/9ntxejv7/8/

anyone can help me? thanks..