1) Go to
https://coinb.in/#newTransaction - this I can manage to do
2) Copy paste an address I want to spend - can do
3) Click "Advanced options" - Total success
4) I can now see the nLockTime, RBF, etc., but as you may expect, I don't know what to do here, and I don't want to lose my coins if I do something wrong
Personally, I would make sure that RBF is selected, as it allowed you to bump the fee if the transaction gets stuck (and you have enough change leftover in the transaction to increase it)
As for nLockTime, well that is simply a matter of figuring out what nLockTime you want... as per the docs, you either use a value less than 500,000,000 to specify a block height that the transaction should be "locked" until, or a number greater than 500,000,000 is calculated as "Unix Epoch Time" (number of seconds since 1st Jan 1970)...
So if, you put nLockTime = 0 (the default for most wallets)... then the transaction is not locked at all... if you put 495000 it will be "locked" until block# 495000 is mined...
5) Generated hex - I assume I'll see some gobbledy-gook on my screen after generating "unsigned" transaction, and that will be the generated hex
Correct, as you've ONLY pasted the "address" and not a private key, coinb.in can ONLY create an "unsigned" transaction... when you click the submit button on coinb.in, it'll simply display a textbox with a bunch of hex... like this:
0100000001bc284061e32979e218b470d8a4676222c5391806cd0dc6a2e582025e880a1616000000006a47304402205dc6f38f650444815f3fca2bb4e6e66c9f9b76d7cf8ee1734d696e98cd3f68740220225d7d31a91344bc4c6ad6f8cfa69fbfd0cb1329391c73076c704b1b3b2cae630121031232d3a27097ca423e3f0b5498416ac30fbad385334ee2306cae2c5de7b6e70effffffff02006a1800000000001976a91449f6714af5764cde99bcab77128971c12ea27f8388ac2c1a0000000000001976a914c439defaa3d4bab40104f42a06faf4d7b404c9ec88ac00000000
6) Load the generated hex into electrum - How, where, when, why...etc. Don't want to lose my coins if I mess something up the first time I try
7) Verify it, sign it, and broadcast it - How, when, where, why...etc..Don't want to lose my coins if I mess something up the first time I try (when sending a transaction normally, I just press "send" - same here?)
- In Electrum: "Tools -> Load Transaction -> From Text"
- Copy/Paste the "hex" and then click OK
- It will display a typical "preview" window, showing the inputs, outputs, fee used, transaction size (and nLockTime if specified)
By "Verify"... I mean just look at the information Electrum is showing you and double check you have it all correct... check you're using the inputs you want to use and are creating the outputs you want (ie. sending to the correct address(es)
"Sign" and "Broadcast" are easy... just click the "sign" button... enter your wallet password... the only thing that will happen is the "status" should change from "Unsigned" to "Signed" and the size might change by a byte or 2.
At this stage, if you are 100% happy, you click "Broadcast" and the transaction is sent to the network... or you click "close" and the transaction is destroyed and NOT sent.
8 ) Manually calculate and specify "change" address and payout - oh Lord....not "the catch"!
Pretty simple... if there is going to be any change (and there really shouldn't be if you're wanting to send ALL your coins)... you simply copy a "change" address from your old wallet (could even be one of your input addresses if you don't care about address re-use etc)... Coinb.in simply calculates the "transaction fee" for you... but using the difference between "Total Inputs" and "Total Outputs"... you just need to make sure that you leave enough difference to create a "decent" transaction fee. Remember, miners care about "sats per byte" or "btc per kilobyte" fee RATE... not the total size of the fee!
Honestly, if you're concerned about using this process, I would suggest you practice with some small amounts of BTC first (or maybe try using TestNet? although I'm not sure that coinb.in allows you to create testnet transactions... I couldn't get it to work)
And if you're not comfortable doing that, then you just need to sit on your hands (and your coins) until the "Dummy's guide to B2X" comes out... By doing NOTHING, you will be guaranteed not to lose any coins... at worst, you'll lose some $$$ as the price of the coins dumps