Since you’ve already purchased you should be able to re-download it again from your account. You won’t have to repurchase it or anything, all updates are free.
It will be labeled just “Epik” (not Epik Pro) on StudioPress. So if you can see Epik in your downloads section then you already have access to the latest version. If it’s not showing up in your StudioPress then you may want to let them know so they can get it fixed.