Standard method for showing changes made to a LaTeX manuscript
When submitting to IEEE journals which require to highlight the changes, I simply colour them in red (no one complained so far...).

\usepackage{xcolor}   
\newcommand{\rev}[1]{{\color{red} #1}} 
%
%...
%
\rev{Hey, I'm a change}


For purpose of reviewing, they just need a compiled PDF. For the final submission, you can simply redefine the \rev command to do nothing.