I'm trying to take a fitness bodyscape of myself like this one:
I've got the backdrop for it and have an Andoer kit for lighting that contains:
I like how the muscles are very well defined in the example and would like to replicate the shot.
How can I use this gear to get something similar?
The subject if obviously lit from above so that the light is at a low angle on the abs and creates dramatic or at least favourable shadows.
Hang you lighting from the ceiling (or put it on high stands) and put your self almost directly under it.
One problem you will have is that if the lights are not high enough they will be much closer to your shoulders than to your abs and your shoulders will be overexposed (or your abs underexposed). So you have to hang the lights quite high (at least twice your height) to even out the lighting, and if the light is far the subject receives less light so you have longer exposures. Your LED boxes may not be powerful enough.
Come to think of it, the lowered head is likely a cop-out. With this kind of lighting you will also have strong shadows on the face and they will make you look weird and distract from the abs. As shot above the face is completely ignored and the viewers can concentrate on the muscles.
Things to note about your image:
I would suggest setting up you shot similarly to this one. If your light-stand isn't tall enough, then get creative in attaching the light to the ceiling. The light should be pointing straight down and positioned just in front of you.
You don't mention what camera and lens you have so I'm assuming a newish DSLR and a kit lens (18-55mm). Set your camera to Manual mode, select f/5.6 for aperture (lenses sharpen up quite a bit a couple of stops down from max). You'll need to play with the ISO and shutter speed to see what works...
30W is, unfortunately, not that bright. The sales page for your lights shows them lighting a sock from a foot or so away. That is what these lights are designed to do: light something small and fairly close...small objects, headshot portraits, etc.
Place an object about where your shoulders would be in the frame and take a meter reading through the camera and dial in the shutter speed, having set ISO to 3200, and see what it is. If a speed of 1/500, for example, is good - than we know that we can reduce your ISO. The shutter speed should be in the 1/15 to 1/60 range or faster using the lowest ISO you can get. Note that, in this range, you'll want to use the Mirror Lock Up functionality of your camera.
Because of the low power of the lights, you may have to start making tradeoffs like using a more open aperture at the expense of sharpness. Won't know until you meter!
I'd remove the light-box for this shot and see how it turns out. If your shadows are more defined than your goal, then you need to soften the light (use the soft box). The caveat here is that your soft box may make the lighting too soft...this would indicate that you need a smaller box or to explore some homemade light-softening solutions.
Also due to the low power of the light, it may be impossible to light your head, shoulders, torso, and legs appropriately in a single exposure. If worse comes to worse, you can always lower the light down and take separate exposures for your head, torso, legs, and blend them together in post. It'd be nice to do it all in one shot, of course, but if you lack the gear, make up for it in post ;-).
Should I also somehow isolate myself since I have white walls around so light wouldn't reflect?
Yes. Your studio space should be dark enough to where the only light the camera records is the light you want it to record from the direction that you want it to come from. Most studios use dark/black painted walls, ceiling, and floor precisely for the reason you describe: white wall reflect light. You can get around this by using a very large and open space or boxing yourself in with dark fabric (think of a human sized light-box).
In addition to Hueco's excellent answer, don't forget to :
