Hi Livegirl,
You will want to use a htaccess to accomplish this rather than a redirect because you are (seemingly) redirecting the entire site starting with what I am guessing is your primary subdirectory.
You could use 301’s, but you would want need to do it on each page.
Also be sure to use the canonicalisation feature to assign one primary domain to preserve link juice. You can read more about that here; Canonicalisation
Why is it that you are doing this anyways? The removal of the dashes will not provide any added SEO element to the URL structure?
Gary