If you have entered some Reasons in error and want to remove them from the drop down list on the Dispose screen, do the following:
Download http://dl.waspbarcode.com/wasp/supportfiles/DeleteRemoveReason.zip and extract it on the server machine.
Edit DeleteRemoveReason.wql in Notepad. On this line:
update reasons set record_status = 2 where description = 'REASON'
change REASON to the reason you need removed, i.e.,
where description = 'Whatever'
If you need to remove multiple reasons at once, change the above to instead be
where description in ('REASON1', 'REASON2', 'REASON3')
You can add as many reasons as needed into the list, enclosing each with single quotes '.
You should not remove the default reasons from the list, just ones that have been added.