Magnetizing your contemptor dread is pretty easy and quick. Check out the tutorial, you'll be suprised at the ease of it.
These are the two pieces you'll be magnetizing. Its the part just past the 'elbow' and the one that fits into the 'shoulder'. Having this magnetized also allows you to swivel the guns and fists so it lets you have some action figure like qualities to the model. Who doesn't love that?
I used 1/8 x 1/16 magnets and a 1/8 drill bit and my dremel.
After that, line up your two pieces and mark the 'elbow' bit so you'll know where to drill. This is so your bits line up perfectly without any guess work.
Here's the mark; just drill it out deep enough to sink the magnet being careful not to go too deep and breaking the bit.
Put the two bits back together and then glue in your other magnet. Easy as that.
Now, for some fancy, I hinged the elbow joint. For this you need some pinning material, green stuff, a tiny bit and a steady hand.
This is the general idea of what you're going to do. A hole all the way through the joint with a rod between them. While holding the bits together, drill through the middle. You need to be careful that your straight because if it is off too much the angle won't let it hinged. Basically as long as it goes in the center of the plate that looks bolted on with rivits and comes out the other plate center it'll work.
Once you get it done, clip your rod to be just a little shorter than the actual width and put it back into the joint.
Then fill both sides with GS or superglue to hold the rod in place.
This joint works on the fist, but works best on the guns. If you hindge the fist, because it is pretty heavy it tends to just flop to the lowest angle. With the weapons, there isn't a lot of range of motion and they're balanced better for it. Good luck, and any questions feel free to comment!