Undo both sections, top and bottom collar as the one you undo is always the one that is stuck. At least that way you have twice the chance!!

WD40 and somtimes a pry bar to get them apart slightly can help if they are stuck, or some help with a soft hammer...
All you need to undo is the 4 bolts to the crossmember, the rack ends and the steering colomn.. It should fall down and smack you then.

Shaun
Shaun