Question

How can we change our blood group?

Answer 1

by eating chicken's liver we can change our blood group a to o group this is really possible

Answer 2

Scientists have discovered an enzyme that is extracted from a strain of Streptococcus pneumoniae. The enzyme is named 98 glycoside hydrolase .
 
It can cut away antigens in blood types A and B, to make them similar to Type O - being considered the 'universal' blood type.This is because every human body can accept type O without causing any life-threatening immune response.

The current enzyme cannot remove 100 % antigen from type A and B, which is why it is not yet used clinically.