I was also intrigued by the capsule and wondered if I could open it and reuse it.
The capsule is in three parts, as you can see from the image. The bottom end goes in first to the machine, the body holds the coffee and the top holds everything in. The color tells you what kind of coffee--black for bold, blue for long (for "long pulls") and green for decaf.
The bottom is just a snap on cap while the top is bonded to the body--there's the rub in opening it.
Step 1: Top Removal
The second method was with a razor knife. That actually gave a better result, but is also a bit more hazardous. Careful and slow cutting of the top, just shaving the lip where it bonds to the body is the key.
Once the top edge is removed it is easy to pull the top out of the recess that it sits in within the body.
Step 2: Capsule Breakdown
The body is shown upper left and you can see the filter screen at the bottom of it.
At the bottom is the removed top piece, shown upside down. It has a filter disk in it. The top piece just slides into the body and sits flush on a ledge the runs around the inside rim of the body.
Step 3: Espresso!
Frankly, the espresso is better from a fresh capsule, but this method works fine if you have coffee that needs to be used up or if you run out of capsules.