To rebalance/make changes to the portfolio you've created: 

1. Tap "Portfolios You Created" in the home tab

2. Tap the pie icon on the top of the screen

3. Here, you can adjust the percentages to the assets the portfolio already holds, including removing or adding securities from the portfolio. You can also change the meta-data of the portfolio, such as description, title, and ticker. 

4. Always remember to review your changes before submitting!