I've been playing Tau for 4 years. For a long time, I've been wedging my XV8 Crisis Suits war gear into the provided arm and shoulder slots and let friction do the rest. Overtime, wear and tear has made it more difficult keeping the plastic pieces stuck in. On numerous occasions, I almost lost a few pieces. It's a real pain after packing up checking and rechecking the table, making sure I didn't leave any pieces behind. After one too many close calls, I finally decided to magnetize my XV8 Crisis Suits.
List of tools and materials:
-Games Workshop XV8 Crisis Suit
-Games Workshop Green Stuff
-Cup of water
-Super Glue
-Cutters
-Modeling Knife
-File
-Point Sink
-Hammer
-Electric Drill
-5/65" drill bit
-1/16" x 1/32" Neodymium Magnets
I bought my magnets off Amazon for $11.99. You may get away with using a manual drill, but I find it difficult working with a 5/64" drill bit.
IMO it's much easier using an Electric Drill.
First off, you should get a stack of magnets and mark them. It makes it much easier distinguishing the two opposite poles so that you don't accidentally glue the same magnet discs facing each other. It also makes it easier when you are magnetizing multiple Crisis Suits and you want each wargear piece to be compatible with other Suits.
Next, you should mark where you would like to stick your wargear on the XV8's main body.
For this demonstration I will be using the left shoulder hard point...
and the right outer-arm hard point.
Unfortunately the shoulder and arm slots aren't big enough to fit the circumference of a magnetic disc.
Drill slot using the 5/64" drill bit and electric drill.
As you can tell, the magnet discs now fits perfectly.
Next, you'll want to make sure the magnetic discs is flush with the surface.
Unfortunately, the arm slot is too deep.
Using your modeling knife and cut off a small piece of green stuff. Mix the blue and yellow strip in water until it's green.
Fill the bottom of the arm slot using green stuff and wet modeling knife. Make sure there's just enough room for the magnet to sit on top while being flush to the arm's surface. You could also add a bit of green stuff in the shoulder slot if you later want to hide the magnet.
Glue in a magnetic disc into the arm and shoulder. Make you both come off from the same end of the magnet disc stack and are facing the same direction.
Now we will work on the war gear.
Snip off the plastic strip protruding from the side or bottom of the war gear pieces using a cutter.
Unfortunately your cutter have not made a clean cut.
File down the war gear pieces until the surface is flat.
Drilling is difficult on a flat surface. A drill bit could easily slip and drill away from the intended area. It's much easier to make a small indent before drilling.
Here I, I stick the counter sink and hammer in a small indent, marking where the drill will be.
Now you can drill your war gear. Start at a slow speed.
Frequently check whether the magnet disc is flush or not. It may help to wrap a small piece of tape around the drill bit, marking how deep you should drill.
Use super glue and apply it into the drilled holes.
Remember the marked end of the stack where you took a magnet off for main body? Take a magnet from the opposite end and the stack and glue it up into the war gear drilled hole. Wait for it to dry.
Presto! You now have a magnetized Tau XV8 Crisis Suit!
Each war gear should be interchangeable between both hard points.
They should also be compatible with other Crisis Suits.
As you can tell, the magnets are strong, even when the Crisis Suit is upside down.
I hope this tutorial has been both informative and helpful.