TRAILS application allows to bring in user-added layers to visualize in the map view for project references or to participate in the analysis. Once the custom layer is added successfully it gets displayed in the list of layers and in the legend. However, it can be tricky to find how to remove a user-added layer at first. To do so:
Go to the “Add Data” panel.
Scroll to the bottom of the panel and find the name of the user-added layer. Then click on the link that says USER-ADDED LAYERS.
A new panel will open with all user-added layers listed. Here you can click on the trash icon to remove a layer of interest.