Search for the device using global search. Then click on the device. You are then presented with the device context page. On the left are the tabs, the top right is device details and bottom right device availability/events and heat chart. Depending on the device type you are presented with multiple tabs, like Details, Health, Response Path Test...etc etc. Some of the tabs may not be relevant, for example if viewing a switch information you are also presented for Firewall tab(s). These tab are probably not relevant.
DX NetOps DX Performance Management
Click on the tab you want to remove. When you select the tab you will also notice a cog wheel icon to the right. Click on it and select Delete Tab. Also there are other options available like Reorder Tab and Restore Tabs To Default. Remember to select the tab you want to delete!