You can just grant them to them the moment the spaceport is complete and then pay one cred.
So I colonize a planet. Do the normal "create a faction" stuff and once the spaceport is complete I somehow gift the colony to a faction and it instantly removes my faction? Okay tested this. I can colonize a planet, wait for the spaceport to be completed. Then talk to the planetary admin and govern a colony in the factions name that I'm working with. The player faction is instantly eliminated afterwards.
you CAN pull an Andrada by refusing to hand over your conquests in quick succession.
Can you ELI5 (Explain to me Like I'm 5) this? Refusing to hand over my conquests in a quick succession. Pull an Andrada? Today I did figure out I can take over a colony if I re-invade it few days after my own faction lost it and pull a Sindrian Dictat in a way, but I think that's not an independent faction, just grabbing the governors chair for a reputation hit.
If you are comissioned and invade a world, it normally goes to the comissioner faction, not you. But then you get two options in the market capture notification. Buy governorship, with it staying with the comissioner, but you administering it (if size allows it, discounted compared to doing it afterwards.) or take it over (hands it over to your faction, gives a rep penalty with the comissioner, based on the market size).
In this context, pulling an andrada is taking over worlds, after your comissioner softens them up, in quick succession, until they break off the comission due to low rep.