Membership Promotional expiration date extension

We originally had our promotional membership expire after 60 days, and then we jusy chaged it to 365 days, However the members who have already signed up are still set to expire after 60 days.. How can we edit the membership expiration date?

Also can we create a membership that never expires?

On the profile edit page, there's a block to edit the account's membership level and expiration.

For custom membership levels, there's a duration text field when editing the level's pricing.