Yes,
as well there is another fast way but you need know the format of bytes in memory - is it either Big or Little Endian, for example:

unsigned int x;

{
unsigned char low, high;

low = ((unsigned char *)&x)[0];
high = ((unsigned char *)&x)[1];
}

This way does not do any calculations but just pointer types` conversion which is the part of compiler -> no processor power is involved.
Good days!