Porting and looking to see how to transfer saved voicemails to GV/another carrier?

[nickacs]

Hi everyone... One of the parts of leaving VZW and going to a pre-paid carrier after buying my Nexus 4 is to somehow transfer my saved/still needed VZW voicemails. But I'm not sure how to do this? Can you do it any easier transferring to Google Voice so then, at least, going forward if I transfer to/from any carrier, I don't have to worry about this since they will all be stored in GV?

I found a couple websites that save your cellphone's voicemails to .mp3 or they will send you a CD/email them to you, but I'm not looking for this kind of service. And maybe it's just impossible, but thought I'd ask

Thanks in advance!