For the morphs watch the video here- hxxps://www.versluis.com/2022/11/how-to-convert-genesis-8-characters-to-genesis-9-using-the-fit-suit-method/
For the textures see here - hxxps://www.daz3d.com/forums/discussion/599256/baking-textures-from-g8f-to-g9
Although it's easy enough to transfer textures with the Blender tutorial it's hit and miss with the male gen textures because of the difference in the UV maps, but that can be put right in Gimp or Photoshop if you know what to do. The female nips will also be slightly off and need moving to match G9 UV'S and any geografts using the move tool.