Click a tool in the Tools panel. If there is a small triangle at a tool’s lower-right corner, hold down the mouse button to view the hidden tools, and then click the tool you want to select.
Hold down Alt (Windows) or Option (Mac OS), and then click a tool to cycle through and select hidden tools.
Press the tool’s keyboard shortcut. The keyboard shortcut is displayed in its tool tip. For example, you can select the Move tool by pressing the V key.