I'm having trouble modifying a partition on my external drive. I have a 1Tb WD external drive. I had put a back up of my internal drive onto the External. Then, I partitioned the External. I'm not sure I did it the best way. I think I first shrunk the original partition down to 750 gb, then added the second partition. I would like to re-size the partitions again, but it wont let me resize the second partition. It says that the partition can't be modified, and when I click info, it says "Owners Enabled: No." Any idea how to fix this?