How to fill a Butane lighter that has cotton in it?

When I take the shell off of my butane lighter there is a flat head screw and another hole. If I undo the flat head screw it reveals a spring which leads to the flint. Other than this there is a little hole which leads to a bunch of packed cotton, I tried picking at it but it seems to be in there pretty good. I assumed that you’d saturate the cotton with butane fluid and this would make it diffuse to the wick. The lighter doesn’t seem to be working though and I don’t want to take any more chances lighting it in case this is incorrect. Can anybody give me advice?