Before you begin, please make sure you have downloaded and installed Hiro Wallet and have some STX in your wallet.
Go to https://minecitycoins.com/ and connect your Hiro wallet
Choose the city you want to mine from the dropdown menu.
You should be brought to this page. The page takes a little time to load. Please be patient.
From here, click the Mining tab.
You should be brought to this page. You can mine one or many blocks (1-200).
Fill out the required fields: Number of Blocks to Mine?, Amount in STX, and check the checkbox that you understand the requirements.
Once you click the Mine button, you should get a message saying the transaction was successfully sent.
You can then click the link below the message "Mining transaction successfully sent" to monitor your transaction.
As you can see, it currently is in a Pending state.
Eventually you will get a message saying "Confirmed in anchor block"
Also in the above image, it tells you which block you are mining. In my case, it would be Block #39933