Here goes...this tutorial is for if you're using the cloth pants on your Hulk. If you're not using the pants, I'll explain the difference later, down near the bottom of the page.
First thing to do is completely disassemble the hulk figure and then trim off all the plugs to get a better joint fit.
Torso section: First remove all the material in the 'socket' of the upper torso. You'll probably need to use a dremel tool to smooth down all the extra flashing. Next split the abdominal section lengthwise. Start gluing the upper part of the ab pieces to the upper torso. Make sure you get them at even heights or Hulk will lean forward or backward (unless thats how you want it). You might want to put in some vertical cuts on the upper sections of the ab pieces before gluing. They have a tendency to bend downward at the top when you bend the edges outward to glue them. After that I reinforced mine with some wire glued between the ab pieces as shown in the picture ->.
After you get the major assembly done, you'll need to do puttying. If you get the ab joint nice and flush, puttying the serratus should be pretty easy. There's still some major puttying to be done to fill the holes between the two ab pieces, between the torso and hip pieces, and some minor filling on the back.
Notice that i've glued the upper most section of the legs to the hips. This worked fine on this particular hulk as the pants were loose enough to get on that way. Since then I've gotten hulks with tighter pants which caused me a lot of trouble :(. So I'd recommend not doing it this way and glue all the leg sections together and just the hips to the torso. Then put the pants on after painting. and then do the final assembly of attaching legs to hips.
Here's a side shot. Once you get this far, with the major puttying done, now's the time to fill it if you're going to. I've used resin as well as 2 part polyurethane foam. Resin's definitely the more trouble free of the two. If you use polyurethane foam be careful of getting pockets of air trapped while it's expanding. I've had trouble with it happening in the upper pec region and around the obliques. Don't forget to plug the shoulder holes before filling.
I kinda glossed over the shoulders part. I didn't really take any pictures of doing them, unfortunately. They're pretty straight forward. Do all your puttying on the hands & forarms before attaching the shoulders to the torso. Then after attaching them, sculpt the deltoids.
Now he's ready to paint.
After you paint him, put the pants on and then glue the legs on.
For painting I started by priming the figure with Krylon Sandable Primer to assure good adhesion of the paint I'd apply later. After that the figure was basecoated with Krylon John Deere/Case Green Farm Implement spray paint. Let the base coat dry at least a few hours before continuing, allowing 24 hours would be best. Next using an airbrush, I highlighted the upper surfaces of each muscle belly with a mix of Badger Model Flex Burlington Northern Green and European Dark Green (more BN Green than ED Green). After this dried to the touch, I started shaded the lower surfaces of the muscle bellys and any deep crevices with Badger Model Flex European Dark Green with a touch of Burlington Northern Green mixed in.
After airbrushing the flesh areas, I used a glaze to bring out the wrinkles and folds of the skin texture. To make the glaze I used Liquitex Artist Acrylics Hunter Green w/ a touch of Cadmium Red Deep Hue. Mix this in with liquitex matte gel medium until the desired tranparency is reached; generally it takes one to two times as much gel medium as it does paint. Thin this mixture until it's a little thicker than heavy cream. Next brush it on to the figure and then wipe off the excess with a paper towel/cloth. You'll want to work in small areas so that the glaze doesn't dry before you get it wiped off.
The hair & eybrows were done using a less transparent glaze of a darker mix of the Liquitex Hunter Green and liquitex cadmium red deep hue.