lowering pitch for bass bridge repair

[Steve Borgstrom]

Hello gentlebeings,

I need to repair a cracked bass bridge on a vertical piano. It is NOT 
cracked by the bridge pins, but just a break on the wood underneath the 
bridge that is attached to the soundboard. I can handle the 
woodworking/gluing part of it, but being a new tech, I have a coupla 
procedural questions:

I need to take the bass strings off their hitch pins, so I assume I 
need to lower the tension on the tenor and treble strings too. Question 
is, how much? 1/2 step, whole step, or till they are loose and floppy 
but not overly loose and floppy? Or remove them all, placing them on a 
wire?

Any other "heads-up" reminders about this kind of repair directed 
toward a newbie are welcomed and appreciated!! Thanks, all!

Steve Borgstrom
Brooklyn Park, MN