I'm not sure if the V240 Service Manual or othe docs found here
will include that - you may need to find a copy of the Field Engineers Guide that includes that model.
Were I in your situation, I'd first look at just replacing the fans and seeing how far that would get me - start by checking noise (dbA) specs for current fans versus likely replacements. But in the end, keep in mind it may be cheaper to buy/trade for a 2500 than rig a V240 for "silent running."
I think replacing the fans wouldn't be so hard except the PSU where I'd risk the destroying of the PSU(s) with a not suitable fan
It's a low-end config with 1 GHz CPU and 2GB of memory w/ disks but in good shape and I have the rails too. I highly doubt that I can trade it even for a Blade 150