Help filing Form 8379

Hi. I filed my 2018 taxes jointly with my husband. We divorced in September 2019. I then filed my taxes individually on 22 April 2020 for the previous year. The stimulus check was released on May 1st and I just learned that it went towards my now ex-husbands child support (from a previous marriage). 

 

Now the big question: How should I file the Injured Spouse Form 8379. I never had to deal with this issue before. Can I mess it up easily? Should I just get an accountant to do it?