Send a request with your NXT address to patmast3r, he's issuing the NEMStakes on NXT AE.  Reminder: you have to send 1 NXT to NXT-97MX-EWKV-CGKX-DA5WH first which is necessary condition to transfer the asset to your account.

Alternatively you can wait for NEM's official launch -- you'll be able to claim your NEM via your BTT account then.