The basic construction is a black pullover from an old cheap store-bought halloween costume, and foam-core assemblies attached with velcro. There's a PVC 'backpack' that has mechanical arms with elastic bands that can flip up giving the General an extra pair of arms.
Step 1: Foam Core Assemblies
The foam core assemblies are sized for a child, but of course could be made larger for an adult. They are cut from paper patterns and most are bilaterally symmetric. Some sections are pre-painted and 'weathered' with dilute black tempera paint to give shadowed 3D effect. I used hot-glue to assemble them, but other glues are fine. When dry, they are aligned onto the body-suit with velcro on the assembly and the suit. The suit velcro should be sewed on (or stapled if you're hasty).
Step 2: PVC Clips
These clips are useful because the allow anything that attaches to the PVC to be removable.
I used these clips in several places in this costume.
The roundish neckguard is held on to the PVC backpack using these clicks. On the secondary arms the forearm 'greaves' use these clips.