Transformation ... Slave to Master

[Paula Saito Telloli Martins]

I have 2 DNS´s servers: one in my main site and the other in my backup site.
 
If I loose my main site for any reason, my secondary (slave) will answer the
queries normally for some time (until the zonetimes expire). But I have some
procedures as contingencies and it´s possible to execute them only from my
Master server. Does anybody know how to find or implement a way where I can
"transform" my slave into master server quickly ?
 
Tks !
 
Paula.