1. First, backing up your wallet in different locations!
2. On your Desktop, create a new notepad file.
    Click on TOOLS, in your wallet, then DEBUG CONSOLE.
3. Secure your wallet by clicking on SETTINGS, ENCRYPT WALLET.
    Enter a password, repeat it, and click OK. (Do not forget your password!)
    Re-run your wallet
4. Enter the following command: "masternode genkey" and press ENTER.
    Copy/paste generated long string of numbers and letters to the notepad file.
5. Enter the following command: "getaccountaddress 0" and press ENTER.
    Copy/paste generated address to the notepad file.
6. Send exactly 50000 URALS to your "0" address

7. Check masternode
    Enter the following command: "masternode outputs"
    Everything is fine if you see something like this
    
   {
      ca5e6dc9aec7a3e546bdd75e608a35235aae52f3b9636309e54829b8fcd, 0
   }
   if you see empty brackets like this
   {
   }
   then you need to start all over again, first make step 6 and then 5.

8. Go to ->Tools->Open Configuration File

rpcallowip=*
rpcuser=YourUserName
rpcpassword=YourRPCPassword
rpcport=7555
server=1
daemon=1
listen=1
masternodeaddr=IP_ADDRESS:7444
promode=1
masternode=1
masternodeprivkey=KEY GENERATED BY COMMAND masternode genkey
addnode=195.54.3.213
addnode=185.20.225.229
addnode=151.248.118.2

Chage it, do not use your local IP address, use your external IP address.

9. Restart your wallet
  Go back to Help/Debug/Console
  Enter the following command: "masternode start"