This is a re-edit of my first 'Ible. Since I am now older and wiser and the comments are really useful I'm making this an anti-instructable.

Step 1: Don't Do It Like This ..

I originally tried to improve the existing antenna .. it broke. These are the pieces.

Step 2: What Not to Use ..

Lan-cable
Aluminum foil.
Multi tool
Glue
Small plastic thingy from a pen that fits the little place on the card where the antenna is supposed to be. (it's there on the foil somewhere)

Step 3: Don't Massacre the Cable ..

.. by cutting off the ends of the cable.

Step 4: Strip the Cable

Remove the insulation and shielding to expose the wires. This is the only good part of this Instructable.

Step 5: How Not to Make an Antenna

Removing some of the insulating plastic from the wires and twisting them together to make one long wire is not a good idea at all. ( I have a picture of that but you don't have a 6 metre display)

Step 6: Buy a Connector, Don't Make One Like This

Make sure the little plastic thingy fits the connection (here is the back of my FON-router but they're all the same)
Pull one end of the wire through the plastic-thingy, remove some insulation and test it against the connection so that you're pretty sure it connects with the pin in the middle of the connector.
Glue the wire in place.
Take five, rest while the glue sets and think about what bastards those makers of WiFi-antennas are that can't make stuff you can use. Unless you're using a better glue than I am.
Wrap the foil around the connector, make sure the foil and wire doesn't connect.

Step 7: Never Plug Something Like This Into an Expensive Piece of Equipment

Plug the connector into the connection and pray. I suppose you could use some ducttape if it won't stay on. Otherwise just get a hammer and smash it all to pieces, curse socioty and run off to live in the forrest like the caveman you are.