First, go to the relative Stripe account and click on Account Settings (1). Then, click on the Connect tab (2) and Connected Applications (3) to show all the applications connected to this Stripe account. Finally, click on the X button next to the TalentLMS application (4), to successfully disconnect your Stripe Account with your portal.
Upon completion, you may go back to your TalentLMS portal. You may now connect a new Stripe account without facing any issues.