You can't have the NT without the OT. You can't have it both ways. If a Christian is willing to throw out old OT laws, how are we to determine exactly which ones are no longer valid? I can't disprove YHWH using the OT as a source, because it's a just a book full of stories. But those stories are mostly pathetic when attached to a supreme creator of the universe with attributes of multi-omniness.
Can we ignore the world-wide flood story? What about Jonah living in the whale/fish for three days and surviving? Are you OK with Joshua's army slaughtering entire towns of women, children, and animals because YHWH commanded it in the OT? I could go on and on, so I have no idea why you would isolate some dumb laws. Do you remember which book in the OT outlined the rules for pooping in the camp before a battle?
Geez...you'd think modern Christians could find better ways to spend their time defending their myths.