Yeah, using coldboot menuhax, if I'm not mistaken.
Alternatively, the present A9LH is very very much easier to install,
way easier than when I first installed A9LH (which was V1 at that point).
I just downgraded + A9LH my clear blue 2DS two days ago,
and it was very easy.
Plus if you are on Rxtools, you probably don't even need to downgrade to 9.2! (only need 2.0 ctr transfer),
so you just need to follow Phailect guide step by step (it'll even tell you when to skip steps)
Read it through first, though.