Whilst you do need testbook or similar to diagnose which blend motor/s are misbehaving,you dont need to "Rip the dash apart" to repair it.LH blend just needs the passenger airbag out along with the centre switchpack.RH or distribution need the instrument pack and centre switchpack out.Both need the radio and hevac panel out too.Not a big job,no need to drill any holes/cut any panels etc.Worst bit is the cost of the motor pack....