Short version:
How do I reformat an external hard-drive (read-only, NFTS) so that I can rw to it.

Long version:
I had a self-built Ubuntu desktop that is now dead. I have pulled out the hard-drives and have bought one of the connector's to convert the SATA cable to USB so I can put the data on my Mac. Unfortunately, my Mac is not able to read the hard-drive for some reason... So, I've decided to boot my old Ubuntu laptop to pull the files from the SATA drive to an external drive then hopefully connect that external drive to transfer the files to the Mac. The external drive is currently formatted as NFTS and I'm unable to reformat it with gparted--I'm guessing that's because it's read-only mode...?

This might help

Ubuntu ext3 SATA -> connector -> Mac OS X

or

Ubuntu ext3 SATA -> connector -> Ubuntu ext3 laptop -> external NFTS HD -> Mac OS X

Any suggestions?