Help replacing through frame sofa slide out motor for 2017 Dutchmen 257RDS

[TMF]

I’ve purchased the motor but can not remove existing motor. Issue is, I can’t access, get a wrench, on top 1/2” bolt. The bottom bolt is easily accessible. The motor is through frame and very close to bottom of interior floor. Looks like I have to cut access door between sink/island which i would like to avoid!
Pls help!
Thx!