Copy the exchange plugins from the BodyPaint\Exchange Plugins\Lightwave\ folder to the LightWave\Plugins\model
Set up the exchange plugin. In the Utility tab click on the Additional drop-down menu and select BodyPaint prefs… Select the texture folder and make sure the path for the BodyPaint.exe is correct.
Open a model or create a new one. Create a UV map for your model.
Create and apply a clean texture of a desired size to the UV. Press F3 to send your model to BodyPaint 3D.
BodyPaint 3D will open with the model, ready to be painted.
Select the brush tool to paint the model with the selected color.
To paint texture, switch the radio button, and select a premade texture from the drop down list or load your own. You can select scaling, rotation, tiling, and other options in this box. You can also change the brush settings in the Active Tool tab.
You can pan, rotate, and zoom on the model without changing the model itself. Try using Alt+holding down different mouse buttons and dragging to achieve the same functions.
When painting complex models, you can enable Projection Painting. In this mode, the texture will be laid on top of the model without distortions by relying on the 3d object's normals. This allows to paint straight lines on a curved 3D surface.
To view the UV of the model inside BodyPaint 3D, switch to the Texture tab, choose Show UV under UV Mesh menu and enable the texture under the Textures menu. You can paint straight onto the UV map in this window.
An important function of BodyPaint is to be able to paint on layers, similarly to the layer system in Photoshop. You can get to the Layer Manager through the Window menu. Here you can create (in Functions menu) and delete layers, change their opacity and blending mode.
Finally, when you are done with your model, or just want to check how it looks back in Lightwave, click on Send Scene Back… in the File menu.
The textured model will appear inside Lightwave. Press F3 to continue working on it in BodyPaint 3D.