please explain better what you have in your array.
This is not a valid array of strings, nor a valid array of anything, nor are the things in it valid hexadecimal numbers. We can't help you if we do not know exactly what you have in the array.
Presumably, you will have to convert hexadecimal string representation of numlbers into actual numbers, add whatever you want to add, and convert back to hex string representations if that's what you need in your result array.
But again, show us exactly what you have in your input array, that is a necessary condition to enable me to tell you how to proceed with the conversion.