Robmck - Yes flame soldering steel is a bit different from electronics soldering.  Assuming that the typeface (type slug) has already come off the typebar, apply the flux and heat up the end of the typebar.  If you are quick, you can wipe the old solder off using a cotton rag.  Don't use a nylon one, it will melt !  This will leave a surface as if the typebar has been electroplated ('tinned').  To remove the solder from the inside of the typeface, apply the flux and heat it whilst holding it in a pair of long-nose pliers.  When the solder has gone liquid, turn it slot downwards and rap it hard on the bench.  The solder should shoot out and the slot should clear.  As a last resort, remove the solder cold with a junior hacksaw blade down the slot.  Once you have put the joint back together with the shim, warm it and add the flux paste - which will melt and be drawn into the joint by capillary action.  Then you can add the solder in the same way.  No solder wick required