How to figure out the coordinates of a compressed G point?
Actually the compressed form in hex is 02 + X_coordinate if Y coordinate is even, or 03 + X_coordinate if Y coordinate is odd; comparing to the uncompressed form is 04 + X_coordinate + Y_coordinate. 

So to retrieve the coordinates from the compressed form, just calculate the Y coordinate by curve equation Y^2 = X^3 + a*X + b, there will be two Y values, then choose the correct one by the prefix which is 02 or 03. 

You will get the actual coordinates of the point.