Note: this may be under a different part of your navigation bar depending on your settings and customization. Contact your Support team or Consultant for further assistance if you can’t find the selection.
Here you will see a list of your Opportunity records. Click on an Opportunity record to open it
Click on Views in the top righthand corner, then select, Ownership
Under Ownership, click on, Set Owner next to the User you'd like to assign the Opportunity to.
This will change the status of this Opportunity to show Current Owner