Basecoat the skin with Word Bearers Red . The colours are pretty close, so you can probably get away with one quick coat.
Wash the skin with 1 part Darkoath Flesh , 1 part Garaghak's Sewer and 10 parts Contrast Medium .
Drybrush with Tuskgor Fur .
Drybrush lightly with Squig Orange and add highlight manually with a brush, where you cannot drybrush.
Selectively highlight with Kislev Flesh .
Add very small highlights of 1:1 Kislev Flesh and Pallid Wych Flesh and specular highlights of pure Pallid Wych Flesh in selective spots.
Pink Flesh
Basecoat with Bugman's Glow .
Wash with Reikland Fleshshade .
Highlight with a 1:1 mix of Bugman's Glow and Cadian Fleshtone .
Apply smaller highlights of Cadian Fleshtone .
Selectively highlight with Kislev Flesh .
Finish with dots of Kislev Flesh mixed with Pallid Wych Flesh , where needed.
Tentacles
Basecoat with 3:1 Ungor Flesh & Wild Rider Red .
Wash with Reikland Fleshshade .
Increase the amount of Ungor Flesh in your base mix and glaze highlights on raised folds, pulling the brush towards the edge.
Add finer highlights with pure Ungor Flesh .
Mix Ungor Flesh 1:1 with White and selectively hihglight the membrane, within the previous step.
Finish with very small highlights of White .
Dark Blue Carapace
Basecoat with Stegadon Scale Green .
Recess shade with a mix of Stegadon Scale Green and Abaddon Black .
Add chunky edge highlights of Thunderhawk Blue to all of the plating. Also add striations on the edges of large plates with the same chunky lines.
With Fenrisian Grey , edge highlight it all again with fine lines. Place these fine lines within the striations from the last stage too.
Apply selective edge highlights with Blue Horror . Make these highlights very selective or even specular highlights. These should be placed on the edges of the striations too.
Finish with a few specular hihglights of Ulthuan Grey on points and particuarly strong striations.
Black Bone Claws/Weapons
Basecoat with Abaddon Black .
Glaze highlight raised areas with Corvus Black & Stegadon Scale Green mixed 1:1.
Add chunky highlights with Stegadon Scale Green .
Apply fine highlights with a 1:1 mix of Incubi Darkness and Administratum Grey .
Selectively highlight with Administratum Grey .
Finish with very small highlights of 1:1 Administratum Grey and White . Specular highlights of pure white are probably a good idea on points too.
Yellow Eyes
First, ensure the area around the eye is nice and dark. Hopefully the skin wash has done this for you, if not pop some Agrax Earthshade in there.
Now basecoat the eye with Averland Sunset .
Highlgiht a smaller area towars the front with Dorn Yellow .
Finally pick out a specular highlight with White Scar .