you are able to transfer campuses, most probably via UAC again as there are limited places at Parramatta and the internal transfer system will not allow it, so its up to the external (UAC) system. susally if you want to transfer to another campus, the internal forms are fine, its Parramatta.
Also, after that you will then have to submit a academic credit form too.
Some people will enrol at Parramatta in units that they know are not full so that there are places so they can get in, even though its technically not allowed. Im not sure if law units are usually full or not at parra, but it most likely will be if its a popular unit.
hope it helps.
edit: it may be possible for a internal trasnfer...i remeber it stating clearly that you arent allwoed to trasnfer to Parra but nows its gone frolm the form or policy...