I am hoping you have prepared yourself for this tutorial by reading the first page, if not go back and read it!
Goto your rez file and pick a rez code for a ponied little girl:
Scroll down to where it says D;Hair- 3 ponytails ;0n head [In 3 ponied girls], or HAIR 138 #3.C ;Hair- bald #2.B;Hair-orange side ponytails [for 2 ponied girls] or #1.A;Hair- ponytail 0n head [for 1 ponied girls].
Look for the number 46 which is on the first line at the beginning of each bobble: [in order of 1 pony, 2 ponies, 3 ponies]
46 is the colour of the bobble so go to Carolyn's Colour Chart and pick a colour you like, if it's a 3 digit code simply go over one of the dot's, but make sure not to go over a comma.
Let's have a look at what you have done by picking a code from Small & Pampered (make sure it is a baby that matches to the type you are hexing), save the Hex Workshop, say no that you do not want to make a Back Up and then open babyz and enter the code. If it doesn't work first time, try a different code.