Drop Table and recreate Permissions
Export the table permission before dropping:

    SELECT
  (
    dp.state_desc + ' ' +
    dp.permission_name collate latin1_general_cs_as + 
    ' ON ' + '[' + s.name + ']' + '.' + '[' + o.name + ']' +
    ' TO ' + '[' + dpr.name + ']'
  ) AS GRANT_STMT
FROM sys.database_permissions AS dp
  INNER JOIN sys.objects AS o ON dp.major_id=o.object_id
  INNER JOIN sys.schemas AS s ON o.schema_id = s.schema_id
  INNER JOIN sys.database_principals AS dpr ON dp.grantee_principal_id=dpr.principal_id
WHERE dpr.name NOT IN ('public','guest')
--  AND o.name IN ('My_Procedure')      -- Uncomment to filter to specific object(s)
--  AND dp.permission_name='EXECUTE'    -- Uncomment to filter to just the EXECUTEs