I've read all the replies and I thank you all. They've been helpful and I think I can replace my old HDD with a bigger one in my Macbook. I would like to post another question though. If I clone, as suggested by the "Ifixit" guide, the old HDD to the new one, can I, at the same time, make a new partition to the new HDD so that it has two partitions? I use Tiger 10.4.11.

Thanks in advance.

Kostas