Open the downloaded BLEND file to start editing your robot. All checkered parts of the robot can be replaced. To replace a part, select it and change the value called "Type" in the modifiers panel. To use a custom part, check the box next to "Use Custom" and select an object with the eyedropper next to "Custom Object". When you check the "Use Custom" box, a template part is selected by default. A good tip is to model your custom part from the template part. That way, your part will have the correct dimensions.

On the left side of the screen you have a menu with 5 procedural materials: "Primary", "Secondary", "Cables", "Glow" and "Joints". Select the material you want to modify and adjust it with the parameters below.

To reveal the armature, go to the top right corner of the screen. You will find the armature in the collection called "Robot". Unhide it by clicking the eye icon.

When you are done creating your robot, a good tip is to convert it to a mesh before importing it to another project file. To do that, select all parts of the robot (not the armature), right click and select "Convert To Mesh". That way, the geometry is realized and can be further modified in edit mode. It also prevents all unused parts from being imported into your other file.

To import the robot to your project file, do the following: Open your project file. Click File > Append > robot_character_maker > Collection > Robot > Append.