1. Start blender, open your model's .blend file.
2. Import the animal whose nodes you want to use.
5. Remove one half of the model using B, add a mirror modifier.mode to Weight Paint (Mode). Switch to the Object Buttons using F7 and in the Draw tab, activate Wire (the one at the right). Switch back to the Editing Buttons using F9.
8. Select a node and start painting its influence onto the model. In the Paint Tab, you can define the influence of your Brush. Deactivate Soft. On the model, Blue means 0 % influence, Red means 100 % influence.
9. If you want to analyse the weight painting, select the old model and select a node to see what influence it has. You can also test your rig by rotating a node and see what happens.
10. Before exporting, don't forget to apply the Mirror modifier.