For those who still don't get it by now, "yukkuri shiteitte ne" means "Do it slowly/easily/at your own pace, okay?"
This pic shortens it to "yukkuri shine!" ("shine" being the imperative form of 死ぬ, 'to die')
The Western Touhou fandom tends to translate "yukkuri shiteitte ne" as "Take it easy". For this less accurate translation, "Die easy!" would be another way of translating it.