There are at least two ways Harry could destroy those Horcruxes. One of them is simple enough. If a Horcrux by definition is an object where a fragment of a soul is concealed then why can’t Harry just get rid of those Horcruxes by just chucking them through the Veil? Jodel of Red Hen Publications wrote, “It stands to reason that’s how you get rid of a Horcrux safely. Let it anchor Tom Riddle’s soul on the other side of it” (emphasis not mine). Sounds like a brilliant idea; however I do not believe J.K. Rowling will choose to go there. It just sounds way too easy for Harry.
What is the other way? We have to keep reminding ourselves that Dumbledore was not the only wizard to destroy one of Voldemort’s Horcruxes. Harry destroyed one also. Tom Riddle’s Diary. When Harry plunged the basilisk fang into the diary, we are supposed to believe that the basilisk venom was what destroyed the Horcrux. But the text strangely is silent and for good reason. It is not venom. We are given a clue a few pages before when Harry kills the basilisk with the Sword of Gryffindor.
But as warm blood drenched Harry’s arms, he felt a searing pain just above his elbow. One long, poisonous fang was sinking deeper and deeper into his arm...He gripped the fang that was spreading poison through his body and wrenched it out of his arm...Even as he dropped the fang and watched his own blood soaking his robes… (Chamber of Secrets, pg. 320).Do you see a pattern here? It is Harry’s blood. The basilisk fang was stained with the blood of Harry Potter. It is through Harry’s blood that the rest of the Horcruxes can be destroyed. This would explain Dumbledore’s words to Harry in the cave, “But your blood is worth more than mine” (Half-Blood Prince, pg. 560). We are never given an explanation for the headmaster’s words and I believe the final novel will give us the answer. The shedding of Harry’s blood to destroy a Horcrux serves as a nice parallel to Jesus Christ, another “Chosen One” who shed his blood for the saving of mankind from evil.
What are the implications if in fact Harry’s blood is used to take out the remaining Horcruxes? How will Harry perform the deed? Does Harry need to simply sprinkle his blood on one of the Horcruxes to destroy one of Voldemort’s divided soul? Will Harry need a Blood-Replenishing Potion just like the one that the medics at St. Mungo’s gave to Mr. Weasley in Order of the Phoenix? Finally what will happen after Harry destroyed all the Horcruxes and Voldemort is standing alone. You have to remember that Harry’s blood flows through Voldemort’s veins. If drinking the blood of a Unicorn, a medieval symbol of Christ, gives the drinker a half-life then Harry’s blood containing the traces of his mother’s sacrifice will present a problem for Voldemort now that traces of Harry’s blood runs through the Dark Lord’s veins. This would certainly explain that mysterious “gleam of something like triumph in Dumbledore’s eyes” (Goblet of Fire, pg. 696). Can the final downfall of Voldemort be linked to Harry’s blood? It would certainly seem so. To conclude, I would say that there is a very good possibility that Harry can destroy the remaining Horcruxes through the use of his blood. He has done it before without any damage or harm.
The only question is how Harry will figure out that he needs to use his blood to destroy the Horcruxes? I would imagine that Harry will simply act on instinct, just like in Chamber of Secrets. If anything all this brings new significance to Voldemort’s words in the Goblet of Fire movie, “Astonishing what a few drops of your blood will do, eh, Harry?”