Yes, plan downgrades can be requested when the target plan is valid for your subscription and current state.
In the client portal, use the purchase or plan-change workflow from the relevant subscription. Downgrades usually do not require an immediate payment unless you also add something that increases cost, such as capacity or another add-on.
Before downgrading, check whether your current users, storage, plugins, domain needs, support expectations, and custom features fit the lower plan. If the target plan does not support something you currently use, the downgrade may be blocked or may require support review.
Pending subscriptions should be resolved or cancelled according to the pending workflow rather than changed blindly.
If you are unsure, contact support with the site URL and the plan you want to move to.