To remaster Salix Live, you could simply use the program Isomaster. You must open an ISO file of Salix Live (for example the one you downloaded) and then add to and/or remove from the modules situated in /salixlive/base, /salixlive/modules or /salixlive/optional. Once you are done, save the modified ISO to your hard drive and use Brasero to burn it on a CD-ROM.