There are two things you can do, firstly select each pin in the schematic where you want them turned off and in the property dialog deselect the visibility check box. You can also do this via Find/Replace, there are some tech notes on Supportnet. Secondly, to prevent this in future update the symbol definition in the library to add a Pin Number 'placeholder', that is a Pin Number property with no value and set it's visibility to off. When you back-annotate from packaging the pin numbers will obey this setting. For symbols that don't have a placeholder the visibility is determined by the Pin Number property setting in the Property Definition editor, in general this is set to value visible as that is what is required for most components.
I had the same problem, solved it by unchecking this option in the Settings/Display Menu :
When that option is checked, all pin numbers are shown regardless of the symbol editor properties config.
When it is unchecked only the pin numbers that are visible in the symbol editor properties config are shown.
to temporary turn of the pin number go to the kyn cmd button in the dx designer and type avinvis then a new window will ask you for the attribute type type Pin Number now the pin number will be turned off or you can do as mr Haroldo said you can disable the visibility in the display settings
but for ever if you don't want the pin number to be visible
while symbol creation the pin number visibility check box should be turned off as mr Davis said
Have you been able to solve your problem with any of these suggestions? If so please mark the question as answered.