Change subscriber to a different plan

Is there a way to change a subscriber to a different plan without affecting the expiry date?

We have a situation where a member with a paid suscription can have the subscription fee waived at his next renewal. I have two one-year plans which are identical except that one has a subscription fee and the other is free. If I 'upgrade' a member from the paid plan to the free plan the expiry date changes to being one year from the date of the 'upgrade' but we want it to be unchanged from the original expiry date.

We also have the reverse situation where a member on the free plan will no longer have the subscription fee waived at his next renewal.

Best way to do this is to use CBSubs Import to import from 1 plan to another. If you've multiple users on that plan and you only want to change that 1 user it becomes a bit tricky. In which case you could subscribe them manually to the new plan then edit their expiration and subscription dates within CBSubs > Subscriptions by clicking the # under the ID column.