Magic !!
I have recently discovered that Uranus has a Surface Gravity which is LESS than that of Earth.
Also - the CORE is damned Hot.
So - I am working on planning a Project, for the Colonising of Uranus -
which will eventually lead to the complete Terraforming of Uranus.
Imagine - a Planet covered with a world-wide Ocean of Water, roughly 100 metres deep.
Lots of BIG Artificial Islands.
All sitting on top of the massive still Frozen "mantle" of solid Water-Ice / Ammonia / Methane.
With a heat insulating "barrier" layer between the deepest part of the Ocean and this Frozen Mantle.
The Methane and Ammonia can be burned to create CO2, the CO2 can be processed to create Oxygen, being one part of the replacement of the existing Hydrogen / Helium Atmosphere.
All that is needed is to use the Hydrogen of the Atmosphere as Fuel for Hydrogen Fusion Reactor Powerplants - and the Helium from the Atmosphere can be used in Stellar Converters, to create Nitrogen Gas for the new Atmosphere.
Also - a QUICK and effective method of seperating Oxygen and Carbon Dust from the CO2 - the Carbon Dust can also be used to cover the Ocean bottom, and surfaces of the Artificial Islands.
YES - You guessed - It is a FUTURE Project. Effectively a Sci Fi Project.