Generally, this kind of thing will work:
zcat /usr/share/man/man1/chmod.1.gz | nroff -man | col -bx > chmod-1-man.txt
zcat /usr/share/man/man8/e2fsck.8.gz | nroff -man | col -bx > e2fsck-8-man.txt
zcat /usr/share/man/man8/fdisk.8.gz | nroff -man | col -bx > fdisk-8-man.txt
