first thing you need to know about RBF is that your transaction must be an RBF transaction to be able to replace it! you can not do it with a normal transaction. it is like this
- enable RBF and make the RBF tx
- if it was stuck then bump the fee
simple and easy through electrum GUI
that walkthrough is not good and i recommend not using it. because it is doing it by "manually modifying the wallet file".
that is a dangerous thing to do. you may end up breaking up something without knowing it.
also the biggest problem with this method is that when you double spend a normal (non-RBF) transaction you can not broadcast it. the nodes will reject it because it is double spend!
in other words all your hard work will be useless as soon as you connect back to internet and try to broadcast it to the electrum node.
in other words, this part:
Open the dummy wallet, and load your saved transaction from file. Then just click on the Broadcast button, and you are done!
That's it, you are done now, your previous unconfirmed transaction will be cancelled, and it will be overwritten by this new one we created, and with a proper fee, it should get confirmed in no-time!
is WRONG.
you can read the first comment at the bottom. you will receive a 258: txn-mempool-conflict error when trying to broadcast your double spent transaction.
https://steemit.com/bitcoin/@profitgenerator/tutorial-how-to-fix-unconfirmed-transactions#@vart/re-profitgenerator-tutorial-how-to-fix-unconfirmed-transactions-20170603t003450255z
