Hard Drive Upgrade

I’m thinking of upgrading the internal hard drive in my MacBook Pro to 160G, so I can add a second partition to boot 10.5. There are two options. One company is offering overnight service: they send a box & pick up the machine, upgrade it, and ship it back overnight. Unfortunately they use DHL for shipping. My other option is to buy a 160G drive and upgrade it myself, which involves removing 21 screws and removing some very tightly wedged parts. Even the guy demonstrating it in OWC’s upgrade instruction video had some difficulty.