How to change the membership price?

If the membership is not sold, the price can be edited by following these steps:

Go to Group Dashboard > Click "Manage" on the group > Group Setup > Membership plans > Click on "Action" button next to the particular membership plan to modify

However, once membership is sold, you would not be able to modify the price.
In such a case, you need to pause the membership plan, create a new plan with the same name and the updated price.