I'm sure you'll get loads of better informed replies - but, just to set the ball rolling, I rather doubt you'll get away with simply retuning the reeds.
I don't do B/C but I thought that B/C was the standard tuning for Double Rays? If so, yours may have already been modified to G/C. Selling it as G/C might be an option, then get another in B/C.
Assuming the C row is the same - others will soon say if it's not - and without looking at tuning charts I think you are looking at replacing at least some reeds, it maybe possible to shuffle others around.
Malcolm