Britney Spears’ new powerhouse attorney is making good on his promise to act aggressively in the pop star’s conservatorship battle, filing court papers on Monday seeking to replace Jamie Spears as conservator over Spears’ reported $60 million estate.

Mathew Rosengart requested for certified public accountant Jason Rubin to take over. Over the course of his nearly 30-year career, Rubin has “managed... financial assets valued over $35 million” and “has experience in working on Financial Elder Abuse litigation,” according to his company’s website. Rosengart also filed a petition for Jamie to be removed from the conservatorship, according to NPR.

The new Monday filing also gives more insight into Spears’ relationship with her father, describing it as “traumatizing, insane, and depressing,” TMZ reported.

This is one of the major steps in Spears’ contentious legal battle to not only remove Jamie from her conservatorship, which has been in place since 2008, but to disband it entirely. Her first win came on July 14 when L.A. County Superior Court Judge Brenda Penny allowed her to retain Rosengart. Still, it’s bound to be a long road ahead, as the hearing on the appointment of a new conservator isn’t until Dec. 13.