I want to change the Class on multiple transactions instead of plowing through each individual transaction?

Hi safariguy. 

I'm happy to help, follow along below:

1. From the Accountant menu > Batch Enter Transactions.
2. Select the appropriate Transaction Type and Account.
   
   
    
3. Open the spreadsheet containing the transactions you need to record in QuickBooks Desktop. Arrange the columns in your spreadsheet to match the order of the columns in the Batch Enter Transactions window.
4. Highlight the information, right-click, then select Copy.
   
   
5. On the Batch Enter Transactions window, right-click the first date field, and select Paste.
   Note: Details will turn red if they are currently not listed in the company file. Select the detail in red and select Quick Add or Set Up.
   
   

I want to add multiple split lines on my transaction

Split transactions allows you to add a single or more additional split lines to a transaction.

1. Highlight the transaction that you want to add split lines to.
2. Select the Split button.
3. Enter the required information for each split in a separate line.
4. Select OK to return to the Batch Enter Transactions window.
5. Repeat steps a-d for each transaction with multiple split lines.

You can find these steps as well as much more information at the following article: Enter batch transactions. 

If you have any other questions or concerns, feel free to post down below, thank you for your time and have a nice weekend.