If your lamp has been stood for some time the flint can get stuck in the flint housing tube, the video will show you how to remove it. Before doing so check if the flint is free by unscrewing the flint housing cap and removing the spring, if the flint is free it will drop out of the tube when you shake the lamp. Put in a new flint then put the spring in the flint housing cap and gently finger screw it back in place, do not over tighten. Adjust it until you get a good spray of sparks when you push in the striker key.
This works for the Type 6, the 6RS and the GR6S Garforth, the only difference being the GR6S has three screws not two.