You got a hexadecimal sring. In hexadecimal there are two characters one byte (each char represents one nibble (4 Bits)). So split the string into pairs of two characters. After this, evaluate these pairs to their respective values (IntToStr() also converts hexadecimal values. But to decide the decimal and hexadecimal representation, IntToStr() needs a $ as prefix). Look in the help for further information:
Copy(),
Pos(),
Delete,
IntToStr() etc.