http://ninijinhuumjzbs3lxrgyxkyi4kne6khgr7ipdd5zoprgejdnl2tpiyd.onion
The process is described in Sprout-to-Sapling Migration . A careful reader might notice a few possible concerns: Some users might not transfer funds on time, which could result in permanent loss of funds as per the recent proposal in ZIP 2003 and #925 , burning all sprout funds from ZEC blockchain.