Upgrading videocard. Using a diamond cutting wheel.
This actually happened to me: recently I needed an PCI-E x1 videocard, as all x16 slots were already occupied. PCI-E x1 cards are being sold but they are rare and quite expensive. I decided to try to upgrade (or better say modify) my spare PCI-E x16 videocard nVidia 8400GS to fit into x1 slot.