Hello if it's a tip bearer only prune the crossing diseased branches out to form a wine glass shape if it's a spur heater prune the same out but shorten the leaders by2/3rds if a spur bearer will usually have 2 apples on a short stem next to the trunk, an old Yorkshire man that pruned our trees said if you couldn't throw a bowler hat through the tree thou hant doun it reeght jezza