$Fd$ from $Gd$, $∃x¬Gx$ by natural deduction

Question

I'm working on a bigger proof using natural deduction and I'm struggling with a final step, which is showing $Fd$ follows by natural deduction from $Gd$, $∃x¬Gx$ ($d$ is a random constant, $G,F$ are unary predicates). No matter what rule I try, it doesn't seem to work. Would greatly appreciate some help.