My Macbook is full

Can't get rid of anything else so an upgrade is needed.

Done a lot of searching around but can't find a free solution to the problem of upgrading the HD. I have an external SATA USB interface, and I would like to copy the complete old drive to the new and then expand the partition to make use of the new space, I really don't want to reinstall everything.

Any one have any experience in the best way to do this ???

Cheers

Cris.