If you have registered for beta program, you'll receive the code and install it normally, it should update itself then from DP to Beta and enable you to report the bugs with your Apple ID (Assuming you can't do it now because you got DP version from 3rd party source)
But when you think about this, there should be really at least DP2 in between before Apple jumps to beta versions. And public beta is, well... Beta, NOT Alpha or DP.