How can I translate a Büchi automaton A to LTL(linear temporal logic) if $L(A)$ is definable in the LTL?

MY idea is : Büchi automaton $A$ ===> QPTL ===> LTL

I know that given any Buchi automaton, we can translate it to QPTL(Quantified Propositional Temporal Logic), formally speaking, For every B¨uchi automaton A over $Σ=2^{AP}$, there exists a QPTL formula $ϕ$ such that $models(ϕ)=L(A)$, and we can decide in PSPACE whether the accepted language $L⊆Σ^∞$ of a given B¨uchi automaton $A$ is aperiodic. It's well known that $L$ is aperiodic iff L is definable in the LTL, so we can use this algorithm to check whether $L(A)$ is definable in the LTL.

but how can I translate QPTL to LTL???

thanks!!