replace Replace backward slash '\' with forward slash '/'

:%s/\\/\//g

copy all lines

gg"*yG

select all

ggVG

cut paste

Shift + V => X => P

copy paste

Shift + V => Y => P

delete

d

go to end of line

$

open 2files

vi -o /path/to/file1 /path/to/file2