I just replaced my couch and theater seats in my 2018. To remove the sofa I removed the bed and spring assembly. Then I removed every screw I could see and the couch slowly came into pieces I could carry outside. Good luck.
2018 Redwood 3901WB pulled by 2016 Chev 3500 HD DRW. Goodyear G114 tires, Moryde I.S., Kodiak Disc Brakes, Splendide W/D, Tire Minder TPMS, Sleep # King.