2010 355QBQ 3rd AC

[OKI Marine]

I have seen several posts about adding 3rd AC units to 5th wheels. Some of the lingo is confusing to me. I watched a few videos on YouTube but on other models and brands. One guy had all of his lighting pulled down......?. One mentioned 50 amp and 240 volts, one 50 amp and two 120 volts, one mentioned needing multiple cold air returns/vents (?) . The 2010 355QBQ back bunk room doesn't really cool down. When we bought the camper new it came with only one AC. The front bedroom had a vent with wiring for an AC. After a week at the beach a new AC unit was installed. To get the back bunk room somewhat comfortable we use multiple fans(3) and one is a 24" drum fan. Has anyone else with this unit installed an AC in the back room? Was it simple? How was it done?