C++float assigned to unsigned long y

I have to write separate C++ expression for:

1) extract the 8-bit exponent field to the low order bits of y, and subtract the 127 bias.

2) isolate the mantissa field in the lower order bits of y, and insert the implicit leading 1.

I am not expecting anyone to provide me with the answers, I only want some tips on how to go about understanding how to do this.