How to claim and use Electrum Bitcoin Cash Wallet
You can use seed phrase or private key to claim BCC/BCH.
Install Electrum Cash Wallet on a machine that does not have your Electrum wallet
Wait until the BCC hard fork has taken place, and a few BCC blocks
have been mined.
Move all your electrum bch wallet funds to a new electrum bch wallet. This will
move only your BTC, and not your BCC, because the BCC blockchain has
replay protection. Wait until the transaction is confirmed.
Enter the seed of your (now empty) old wallet or private keys in
Electron Cash. Since the BTC have been moved to a new wallet,
entering your old seed in Electron Cash will not put your BTC funds
at risk.
There's a minor problem that occurs when electrum bch is started for the first time: it will follow the wrong chain of the fork initially.
The client is still completely usable, but it requires user action to select the electrum cash chain after first startup. Safety of your coins is in no way affected by this problem.
This will be corrected in future versions, but for now we offer this workaround (which is very easy to do)
What's the problem?
When electrum cash wallet doesn't find a local blockchain_headers file (which is the case on first start), it tries downloading it via http. We forgot to change that url so it still points to a file that contains the legacy chain headers. When that file is downloaded, electrum bitcoicash will disconnect from the BitcoinCash chain servers because they don't match what the downloaded file says. It then switches to using legacy electrum servers and verifies the headers and now follows the legacy chain.
How to fix it?
Right after startup (or any time, really), go to the Network Window (it's reachable from the Tools menu or the Network indicator lamp on the lower right). On the Overview Tab of that window is a server list. If a chain split is detected (which should be the case), the servers are grouped by a branch id. Select the correct branch (the one that has servers electrum-abc.criptolayer.net and electroncash.cascharia.com) by right-clicking on the correct branch id (that long number with the @ sign in it) and select "Follow This Branch" in the popup menu that opens.
ElectonCash will then follow the bitcoicash wallet electrum branch of the fork and you're good to go!