To rename a gallery, simply go on to the gallery and click on the Gallery Settings option on the left bottom of the screen.

Navigate to the General Settings in the two tabs above and scroll below.

Find the Rename Gallery button.

Simply input the new name and hit the Rename button.

Once an album inside a gallery is opened, the column on the left gives multiple options you can navigate through.

Click on the Album Settings option that lets you edit that album details after you have made it.

Simply input the new name and hit the Rename button.