@NathanB1 The option to change plans to a different one than the one you are currently on should be there by selecting Plans/Add-ons from left side and then Change My Plan. Unless you currently are on that plan and trying to do an early renewal? Then you need to select Change at Next Renewal option to a different plan and then you will see your current plan available again.
BTW, it's also advised to Change at Next Renewal as PM doesn't refund for any unused days left in the current cycle and also immediate plan changes forfeit any rewards until the following renewal.
