How to override the Windchill promotion request form delegate

I'm tying to add additional checks that will run before a user can complete the promotion request wizard.  These should validate that (a.) the user did not select themselves and (b.) at least one person has been selected for each of the promotion request roles.

I would prefer to stop the wizard from completing vs. trying to catch these problems after the workflow has started.  From what I'm reading, this seems to be possible by overriding the promotion request delegate.

There is a sample code snippet by @BhushanNehe here:

https://community.ptc.com/t5/Windchill/How-to-stop-a-User-selecting-himself-as-an-Approver-in-Promotion/m-p/144787/highlight/true#M17171

There is also help documentation here:

http://support.ptc.com/help//windchill/wc111_hc/whc_en/index.html#page/Windchill_Help_Center%2FWCCG_BusLogicCust_WorkflowAdmin_MultPartSelectWizard_Sect3.html%23

I'm guessing I need to create a Java file, compile it, and then register a service, but I'm not sure how to do this.  I'm not a developer...

Would someone be willing to walk me step by step through how I override the Windchill promotion request delegate and actually implement these checks on my Windchill system?