Just got my MBP from repair after almost 2 weeks. If you remember i had problem I could not install OSX. Guess what was the problem? They changed DVD drive and HDD and the problem was exactly what I told them, DVD was scratched and was unreadable. Anyway, here is the issue I need help with. I just bought WD 500GB Scorpio Black HDD (7200rpm). I need to swap my drive, but I do not have Snow Leopard OSX DVD, I have to wait around 5 days to get my replacement DVD by post. But the temptation is just so bad. Is there any way I can do this using only lets say External HDD? Since I have no OSX DVD there will be no way for me to boot to disk utility. What should i do? P.S Is it necessary to reinstall system when you change hardware like HDD?