[OT] Installing 8.3beta on debian (stable)

I have recently been convinced by a colleague to use debian (stable)
for our server.  Now, I would like to install 8.3beta.  I have been
running 8.3beta on another server and it (as usual) is quite stable.
How do I go about installing 8.3beta (using apt, if possible) on the
debian stable?  Feel free to tell me to ask on another list/forum, if
that is the best answer.

Thanks,
Sean