If you know someone, who in turn knows someone else or, knows for him/herself where and what and how to do...(again, talk to HADID!!!) you may be able to do it even in a couple of hours.
Give them as much info as possible in advance...and any last minute change may turn out to be no problem at all.
On the other hand, with the steadily changing situation, i.e. the just implemented contingency routings, you may face some inconvenience.
Why not contacting any of the mentioned professionals and ask for their recommendations and advises?