I have the original Vitamix stainless steel blender with the blades inside the blender. I have a pareve and a dairy one. Can I kosher it for Pesach? What about the plastic cover? I have never put in anything hot in th blender.

ב"ה Shalom Since, I don't have all the details of your blender use, although nothing hot was used, best would still be to immerse the blender container in boiling water, after it is thoroughly cleaned to remove any possible Chametz particles. The plastic should also be immersed in boiling water. All the best, Happy and Kosher Pessach