Ya, drain your tank, it'll make netting so much easier
Put your rock in the mentioned brute containers while netting
I'd be inclined to keep the skimmer on the DT as you want to keep that tank fed while fallow. Find another skimmer for the hypo if you feel it's needed, but a couple HOB filters will do just fine
Get them into your sump now and seed the foam blocks. If you can't wait for them to seed from the DT water, get some startup stuff to help you over the ammonia cycle
And the mentioned ammonia badge and ammo guard or similar is a must
Lots of water changes the first couple weeks may be needed
Treat the DT like you would if the fish were still in there;
Water changes, testing, etc, and feed whatever corals there are that need it
The only thing I see about your plan that would make me nervous is the chance of contmination from splashing DT water into the hypo section
Lastly, I believe the preferred salinity for hypo is 1.009
A Hyposalinity Treatment Process
Best of luck
