Child maintenance appeal

[guccihandbag]

Hello, I'm new to this site so apologies if I'm posting in the wrong area but was after a little bit of advice.
I have 2 children who I have bought up alone. The absent parent has never been involved and we've had no contact in over a decade. He had to pay maintenance via a deductions of earnings order when the CSA were involved as he told them he didn't want to pay. In all those years I never asked the CSA to review the case or anything. Just want a simple life without any hassle.
Since the case moved to the child maintenance service, they take the absent parents income details from the HMRC and calculate maintenance payments accordingly. During the first year with the CMS the absent parent disputed the amount but this was rejected by the CMS. Following the annual review this year he has disputed it again which the CMS once again rejected. I received a letter yesterday from the CMS letting me know that he is appealing and it will go to a tribunal.
I just wondered if anyone has been through this and what it involves? What the outcome was? Is there anything I will need to do during this process?
Thank you for reading.

[Collaborate]

Have you seen this: www.gov.uk/social-security-child-support-tribunal/appeal-tribunal

[guccihandbag]

Thank you Collaborate, will have a read of this.