I got it, if I want to modify my 7452 into 220v version, I need to replace the WHOLE lamp house (which includes the fan), the lamp, AND the power unit.
This is really a pain. I will simply buy a 120v analyser pro, and a 220v - 120v transformer.
But this leads to another question, will the 220v-110v transformer affect the enlarger's light output stability???