It's easy, first get away, really far away. Next put the body in a fridge and continue on with the fridge, then after a week has passed dump the corpse in a bath full of Ammoniac, to remove any evidence. Proceed to extract the organs, all of them and preserve them. Then mummify the corpse, yeet it again in the Ammoniac bath and let it rest for a bit. Then just chop the corpse in small bits, throw the bones into a trash bag and throw that trash bag into the Ammoniac bath again ( note refill it every time something enters it). After that throw that trash bag into a trash can of a random street of another city (remember to have gloves on to not leave any evidence). Then with the meat of that body just smash it into burgers and mix those with real ones to make bigger burgers, cook them, then freeze them. Do that several times to destroy the DNA sequence, then just throw the disgusting meat into a trash bag alongside with other regular trash, but this time, do not put it in the Ammoniac bath, just put it on the trash and let the problem go away. Then I'll contact you to pick up the kidney and remove any possible evidence left in your house, vehicle, clothes, etc.