All changes to your billing can be made from the My Subscriptions window.
You can access this from the switcher.
If you have a single subscription, you will directly see the Subscription Summary. If you have more than one, you will have to choose the Subscription you wish to manage as shown below. 
Select Edit next to the Plan and User section on the screen.
Under Plans, click Change Plan. Choose the plan that best fits you.
The new plan appears with a breakup of the billing amount based on the number of users you need. You can also find the total cost breakup including add-ons on the right. Click Update Subscription.
The updated billing information appears with a success message on the top.
Note:
- When you move to a lower plan, data associated with features in your current plan would be lost if the same features aren’t available in your new plan. Before downgrading, ensure that you are aware of all the data policies around your products’ features.
- Your changes will only be effective from the new payment cycle, that is once your current subscription period ends.
- If you do not have a credit card saved on file (you are an offline paying customer), you cannot move to a lower plan online. Please write to us on [email protected] for support.