We don't know that...he orders the release, it passes down the chain of command to finally reach the file clerk/clerks who pull the files.
At any point along that path DS and Fifth column gov employees can slow walk the process both down and back up the line, adding objections, reviews, excuses, etc to not do their jobs.
Too many here think POTUS has a virtual filing cabinet at his finger tips.
I agree, the comment above that says it would only take a secretary five minutes to do this is a hoot. Things only happen rapidly when something like a rope is hanging in a NASCAR garage.