How do I change my current plan to upgrade or downgrade?

You only need to go to your Account settings and click on Change Plan.

You can upgrade to a higher plan anytime. We will issue a 1-time invoice with the difference for the current billing cycle and the next renewal invoice will reflect the conditions of your new plan.

Downgrading is possible too under some limitations. If you want to downgrade please read Can I downgrade from my existing plan to another.