This is considered a wire hack in order to enable/disable/add certain functions to the circuit being worked on, often times used in volt modding.
Use a fine wire (hard drive and floppy drive cables are usually used since they're very fine and easily obtained), the lead should be as wide as the leg of the IC. Either strip off the shield or pinch it off with your nails, exposed lead should be as long as the leg of the IC you're working with.
Twist the fine leads into a braid so they don't come apart when being soldered. Put a tiny, tiny blob of solder at the very tip of the wire, and clean your soldering iron (precision is required). The blob should be as wide as the leg of the IC.
Hold the wire so the blob touches the leg of the IC, press it with the very tip of your soldering iron to melt the solder. After the solder melts and flows, you may remove the iron, but keep your hand there and hold the wire firmly! If you release your hand too early and the wire moves around while solder is still liquid, it may cross over onto the other legs and short out the circuit.
A finished joint should be clean and away from other legs, no excessive solder should be seen. This process needs precision and it's tough to re-do it, so be extra careful and finish it all at once. If you have shaky hands, clap, one strong clap is all you need, this reduce some of the shakiness (thanks to InSanCen at XS for this tip). After the joint cools and cures, you may secure the wire into place somehow, but it is NOT recommended to insulate the joint because removal will be very tough, as long as the wire is secure into place, the joint will not be touching anything or fall apart. Solder is used to make electrical connections but not mechanical joints, so secure the wire with something durable.