When a block that has a transaction with change in it is successfully mined, is the change transaction included in the newly mined block? If not, how is the change transaction processed?
There is no change transaction type. 

Transactions are defined as a list of inputs consumed, and outputs created, and the values assigned to those new outputs. The creator typically makes an output for a entity they wish to pay, and another output which pays excess change back to them. 

Any amount of Bitcoin left un-used by the outputs is interpreted as the fee for the transaction.