A Kolea with a leg injury, but can still fly, is nearly impossible to catch for treatment.
If the bird cannot fly, and you can catch it, put the Kolea in a ventilated shoebox or pet carrier and bring it to Feather and Fur Animal Hospital in Kailua.
Veterinarians there will determine if rehabilitation is possible. If so, Hawaii Wildlife Center will take care of the bird until it can fly and forage.
On Kauai, the organization, Save Our Shearwaters, located within the Kauai Humane Society, helps all injured native birds, including Kolea. Call for instructions.