A journey from Kuala Lumpur to Kuala Terengganu can be reach via two ways - either by road or by flight. If you got a surplus budget, go get a flight, much more easy and short time taken. If you from outside Malaysia, (read: Getting to Malaysia)
The journey from Kuala Terengganu to Redang Island via boat service. The take-off point located north of this town, which exactly located at Merang jetty. Its about 45 kilometers journey. Anyway, you actually can also get a flight directly from Kuala Lumpur to airport in Redang. (guide: Redang Island)