Start by taking the tip of the wire and bending it to the size you want your Death Star. Then you take the tip of the circle and bend an even smaller circle on the inside with your needle tip pliers. The biggest circle ended up being 20mm. The smaller circle ended up being 10mm. After that take the wire on the other side and bend to the size of your finger on the mandrel.
Here is the finished product! May the Force be With You!