Method 1 - Magic Wand Tool:

This is a very fast form of extraction provided the background is of similar colors. Duplicate the layer of the item you want to isolate, make the old layer invisible. Working on this new duplicated layer > select the Magic Wand tool on the left and click on any part of the background that you wish to remove.

You may try different values on the Tolerance. Once you selected the whole background, press Delete.

Method 2 - Lasso Tool:

Duplicate the layer of the item you want to isolate, make the old layer invisible. Working on this new duplicated layer > select Polygonal Lasso tool and start to point along the edges of the subject. Double-click on the left mouse button once you are ready to close the selection.

Select > Inverse. Press Delete.