If all you really need is to change the working directory, then you can use
However, I'd point out that normally in HTML, paths are not specified using
are found in an "Images" directory contained in the same directory as the
HTML document, then paths of the form "Images/..." are used).
If you have the option of not starting with broken HTML in the first place,
I think that would be best.
Of course, the other thing to keep in mind is that HTML is meant to be
hosted by an HTTP server. Even if you can change over to true relative
paths, you are still limiting your options. If this HTML is eventually
going to be hosted by an actual HTTP server, then it may be that for
testing purposes you ought to just have a test HTTP server host the page
and use proper host-relative paths. In some cases, you will still stick with
the "Images/..." form, but this way you also have the option of using paths
that start with "/" (i.e. are relative to the host, not the page's path).