If I remember rightly, the "not for sale" was only an option
when your adding the domain to Sedo. I haven't seen it
anywhere else.
I have done 2 methods, not sure if there is a better way.
First time, I just edited the description to say "not for sale" and
moved it to "make an offer" instead of leaving the price there.
Second time, I went to domain management and ticked the
domain and at the bottom in the drop down I selected "delete this domain"
BUT, I never changed my nameservers, and it was only for a week.
When I listed it again, I just went to add a domain, and no wait time
because the nameservers were still there.
Hope it helps
