COURSE 2 - 8.2.3. CoinJoin: 2nd step (the leader)
QUICK INFO:
The leader (participant 1): after having received all unsigned transactions by the other participants (2 and 3), in Electrum "Tools" > "Load transaction" > "From file" > selects his unsigned transaction > "Combine" > "Join Inputs/Outputs" > select source if necessary > "Read file" > selects the transaction of participant 2 > "Load transaction" "Combine" > "Join Inputs/Outputs" > select source if necessary > "Read file" > selects the transaction of participant 3 > "Load transaction" > the CJ transaction is now set up: there are n identical outputs of the same amount (with n = number of participants) > "Sign" > write/paste password of Electrum wallet > "Ok" > "Export" > "Export to file" > "Save" > "Ok" > finally, he (the leader) sends the CJ transaction with his signature (but whose status will be "Unsigned" until the last signature is made) to the next participant according to the signing order agreed.
2nd STEP: the leader of the Bitcoin CJ transaction saves in his/her computer all unsigned bitcoin transactions he receives from the other participants. In Electrum, he opens his transaction and combines it with those of all other participants. In this way, he creates a CJ transaction. He then signs the CJ transaction and sends it to the next team member (according to the signing order previously agreed) for signing.