Step 1:
Launch a proof of stake altcoin. For example bitcoindark clone or something
Step 2:
People mine that altcoin until the proof of work period is ended
Step 3:
People send their coins to a burn address
Step 4:
You send the new 100% pos coin to the addresses they send to the burn address with proportional to their coins.
For example i send 18324 coins to the burn address using my address i get sent back same amount i burned to the same address on the new chain
Step 5:
People import their addresses to the new chains wallet and rescan
Step 6:
You have achieved your goal
Source: This is how the Stakecoin distribution was and i got my coins and was worked good i am like it because it was like magic and stuff.
This approach works better if the coin being mined is multi-algo. 4 Algos would make it very fair, scrypt, sha256, x11(or a different GPU algo), and a CPU algo that no one has a GPU miner for.
PoW period should not end as a snapshot can be taken at any point and the new coin allocated based on those numbers. The coins don't need to be burned either.
Mining isn't really a fair way of distributing anything. CfB's method of mining via MS is a bit better because there is only so much damage that unfair mining advantages can do on the NXT system in 24 hours over 1000 coins. But even mining on MS as long as it is open to anyone will still get gamed.
It makes me wonder what is going on at NXT, that it came up with such a great answer to POW but implemented it so poorly and now has brought POW back into NXT. One right step forward and two wrong steps back.