Model usage

Appending the model into your scene is straight forward. Simply appending the welder group to the new scene will include all pieces.

Textures

The GIMP xcf files have layers for each texture element (dirt, scratches and so on) and are organized in layer groups, one for each texture type (diffuse, roughness and bump).  After making any changes to the layers you export the texture based on the GIMP file name and layer group name. For instance, the diffuse layer group in the 'welder helmet.xcf' is exported as 'welder helmet diffuse.jpg' [GIMP xcf file name] + [layer group name] + .jpg Use File->Export As... in GIMP to export the texture.