I need to renew the stem packing for a toilet stop valve. Access and visibility are very limited. Is there a special stubby wrench or deep well socket that plumbers use in these circumstances? It seems to be 3/4" but I am not certain of this as wrench handle length is in the way. I am having to work behind me in the blind while sitting on the commode using right hand only. Also how many turns of graphite packing is recommended?