What do I need to do to use the new SegWit addresses? I looked in the Send section and it is all still the same: Pay to etc and control over the transaction fee...
You need to generate the SegWit address from "send" section first. There are 2 types of SegWit address, which are
1. P2SH-SegWit (sometimes called segwit address or p2sh segwit)
3NhtbwQZ71yHyE7y1eanttNbkHPkusdATD
2. P2WPKH (sometimes called native segwit or bech32)
bc1qlfyx65dyc8usd0m0p682yght6dy9gqvn3ttx7z
P.S. i don't remember if you can generate SegWit address from wallet.dat created by older version of Bitcoin Core (before SegWit is supported by Bitcoin Core)