Open up your Waves wallet.
Go to the Portfolio.
Find issued token and click on the button.
Click on the Token Reissue button.
The following window will appear.
Choose the required number of additional tokens and click on the Continue button.
Note: You can disable the possibility of issuing additional tokens by selecting the Non reissuable. But keep in mind after that, you will not be able to reissue additional tokens.
The following window will appear. Check the entered data and if everything is ok, click on the Confirm button.
After all you will be able to find the reissue transaction in your Transactions.