How to turn small planets and moons into 1 g worlds.

Its sort of engineering feat one should imagine.  The idea is to take heavier matter, and then change the density ratio of a planetary and moon interior so that its gravitational field is altered.  It seems like if you could geo engineer a planet on a large scale importing mass and heavier matter to plant to bury in its mantle and core, potentially increasing its mass density ratio, you could try to create a planet with a stronger gravitational field.  Of course, it seems this could be problematic if your moon were rotating around say an earth like world, where then gravitational tides would certainly increase not to mention the problematic aspect of angular momentum in relation to nearby celestial bodies, which would have to be worked out.  Raining matter on a planet or moon, then burying it into its interior.  Anyways not sure if its possible...the other part of this problem is the amount of energy that would be required in transporting all this material.

To build the Death Star, input energy both light and matter into a black hole, until it builds up enough energy/mass into the system to provide something like 1 g then build a protective shell/ring around it that serves as the planets outer crust.  Thermal radiation released from the black hole provides internal mantel heating, and energy source for life on the planet, and could even serve as a part of a planet's propulsion system (?).  Is it possible?!  Sort of a planet/collapsed star all in one.  I imagine you might need some corrections to the overall shell/ring if its somehow displaced by an impact event which causes any sort of displacement in its position relative to its given black hole interior. :)