Before we start; some important things to point out are:
It is possible that you only have one account in your NEM wallet. If so, you will need to create at least one more account. This account will be the account that initiates the multi-signature account creation. You will also need a set of account addresses to be the additional signers. For the purpose of this tutorial, I have created three accounts, and I will refer to them as signer1, signer2, and MSA (short for multi-signature account). As you might have guessed the MSA account will be converted to the multi-signature account and I will form a contract such that the signer1 and signer2 accounts both need to approve expenditures from the MSA account.
The first step is to login into the signer1 account from your NanoWallet. Click Services in the top panel and thereafter click Convert an account to multisig as illustrated in Figure 5.
The next step is to convert the MSA account into a multi-signature account. First, you need to put in the private key of the MSA account. Then you can add signers, I will add the addresses of the signer1 and signer2 accounts. I will also set the Min. signatures to 2, this means that both signers need to sign a transaction. Start the contract conversion by pressing Send.
Congratulations! We have now created a multi-signature account with two signers.
The editing of a contract is straightforward. To do so you need to click on Services in the top panel and when the creation of the multi-signature account has been confirmed by the blockchain network, Edit an existing contract is enabled for you to click. You can select a contract from Account to edit, and edit the contract accordingly to your needs (adding/removing signers, etc.).
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