Tried to clean the burner heads but couldn’t remove screws. Cleaned them while on stove but didn’t help the uneven flames.Purchased four new orfice holders.all the screws in burner heads broke.tried to remove with left handed drill and tried ez outs with no avail. Hence the purchase of new orfice holders. used a self tapping screw to make threads in the holders before installing and made it easier to attach burner heads after installing the orfice holders. All flames burn like they did when the range was new and wife is happy and I didn’t have to buy a new range.