Ways to change the default Blizzard frames?

[Frizzle]

A long time ago, I was working on a mod that replaced the default Auction House frame. This was before all the changes such as load on demand. I quit the game but recently rejoined and would like to continue work on this mod but I'm still learning about all the new changes and new ways to do things.

Is there an easy way to change the default Auction House frame and their methods completely? What I did before was just move the original frame off the screen and display mine. Then I realized you could hide the Auction Frame with HideUIPanel() as long as you hooked into the OnHide event of the frame and made it not close the auction house.

Now Blizzard changed their auction house frame to load OnDemand. I would like my mod to be OnDemand too and basically replace their default frame and their methods. Is there a way to make it so the default Blizzard_AuctionUI doesn't load or can I simply override the files in that directory? Or will I have to do something similiar to what I did before and hide the default frame and hook into the default functions?

Thanks!