Is it difficult to convert a 28-speed road bicycle into a single speed bike?

Is it difficult (for someone with decent mechanical skills) to convert a 28-speed road bicycle into a single speed road bike (like the Giant Bowery or the Schwinn Madison) by switching out the cranks (or removing them) and removing the derailers?
Update: Okay...not a 28-speed, I meant 24-speed. It was about 1:00am when I wrote it, cut me some slack :)
8 answers 8