Answer:
http://www.petgroomer.com/Grooming101/Breeds/english_cocker_spaniel.htm has full instructions!
you would have to first bath it then dry it then you have to brush it then get dog clippers and the proper size would be
one or two depending on the length of hair
There's a great set of videos on youtube showing how to do this. Here's the link...
http://www.youtube.com/watch?v=TODYMr_qQdw&NR=1