That should do it, yes. Tiger doesn't have the HFS+ enhancements that Leopard has (namely non-destructive dynamic partition management), so although in Leopard you could just go to Disk Utility and delete the partition there and then resize your OS X partition back to the full disk size, you cannot do that with Tiger. Using the Boot Camp Assistant will be your best bet.
If that, for some reason, doesn't work, then you will need an empty external hard drive and Carbon Copy Cloner.