take a brick of sodium from mineral oil jar using long tweezers. Put in on some fireproof dry surface that can act as a cutting board - e.g. glass or ceramic or piece of metal. Without cleaning it from oil, cut off from the brick the chunk of approximate size that you may need, return the rest of the sodium brick back to jar with oil. Weight out the chunk that you cut including the crust still wet with oil, this will give you idea how much you may need to remove to get to the amount of clean metal that you need. Then still wet with oil, cut off the crust, weight again the piece without crust, to see if you have the right amount, slice it into smallet pieces, dip them into a small beaker with hexane, fish them out with long tweezer and throw them into the reaction flask with N2 or Ar atmosphere (the cleaned pieces became much more reactive toward air and moisture once degreased in hexane).

The leftover cuttings and crust should not be returned to storage jar of sodium (it is not a waste container) but liquidated; put them into waste hexane, place it into a secondary container like metal tray and have ready some piece of glass or metal plate that can serve as a lid if necessary. Then add slowly iPrOH to hexane with cutting, to get reaction that isnt too fast (if sodium is turning into silvery bits zipping on the surface, you added too much iPrOH and it may ignite, have a metal plate at hand to smother the flame if necessary) Finally when sodium cuttings expire after an hour or so, you can add a mimimal ammount of methanol or water, to see if it comes back to life - you should make sure your cuttings are properly quenched before pouring the mix into organic waste, obviously