Upgrade HD to MBP and Mac OS installation

[poredoor]

Hi, I need your helps.
I am a newbie to mac. I just bought MBP. I would like to upgrade hard drive to 320GB. I want to do by myself.
1. I would like to know in case I have to send MBP back to apple store. Would warranty will be cancelled according to I upgrade hard drive myself? Or if I change the it back to the original hard drive, it would be okay?
2. When I buy a new hard drive. What should I do with it? I have to install mac os first?
Thank you for your helps.

 

[iBookG4user]

1. I would like to know in case I have to send MBP back to apple store. Would warranty will be cancelled according to I upgrade hard drive myself? Or if I change the it back to the original hard drive, it would be okay?

The warranty is not voided by replacing the hard drive. Although, Apple will try to blame problems on the 3rd party hard drive, so it is best to swap it back to the original drive if you send it back to Apple.

2. When I buy a new hard drive. What should I do with it? I have to install mac os first?

If you have a hard drive enclosure handy, stick the new hard drive into it and connect it to your MacBook Pro. Then use Carbon Copy Cloner to copy the old hard drive onto the new one. If you don't have a 2.5" SATA hard drive enclosure, I bought one for I believe $7 on newegg, so it would be a worthy investment. And you can always stick your old MacBook Pro hard drive in it for an external hard drive