My Leia fix for Episode 9
My idea is in the opening credits say that Leia has become gravely ill and she was put into carbonite to slow down the effects of the illness.
Luke goes in search of the darkside power that Palpatine told Anakin about, about stoping people from dying luke finds it but to do it he has to transfer her consciousness into a new body, Lieutenant Connix is chosen/volunteer/forced to do it.
It works but also drives Luke the the Darkside Luke ends up killing snoke and becomes kylo rens master. Then it all comes down to a battle between brother and sister in a battle between dark and light, Luke Vs Leia