Hello and welcome to MobileRead!
First, did you install the noDRM plugin from here?
https://github.com/noDRM/DeDRM_tools
Second, I suggest you read this post
https://www.mobileread.com/forums/sh...61&postcount=1
Third, if the book is in a fixed-layout format, converting to Word is probably not going to work (the result will be a mess).