That was well nigh impossible. GUI fail, on gparted's part.
These steps won't be 100% complete because it's 7:15am and i spent the last hour frying my brain on this stuff (after the brain unilaterally called a break about 2:15am and i fell asleep), but they do fill in some gaps other resources out there don't quite cover. Some even seem to (falsely) suggest that unallocated space must be made into its own partition first. Here are some of the better links; my (final working) steps below.
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