C language help please!

I am currently learning about inline macros and bitwise operators in C.

I need to complete a program that takes in an unsigned int and converts it to different bases (binary, hexadecimal, and decimal) based on the choice of the user and then completes a number of bitwise operations using inline macros. I need to a) exchange odd bytes while leaving the even intact, b) exchange even bytes while leaving odd intact, and c) find the complement of the number.

example output:

swapping even (binary):

number before: 00110011001000100001000100000000 number after: 00110011000000000001000100100010

I figured out an inline macro for hexadecimal numbers with the help of my school lab, but I'm looking for more help with binary and decimal. I would like to figure this out mostly on my own, so I'm more looking for abstract help or ideas on how to approach the problem.