Cut your chunks of candle gel out of the container and put them into your melt pot. (I made about 16 ounces of ice cubes here.) Melting gel wax is one of the few instances where you need to melt your wax over direct heat. (You can also use a Presto Pot.) But since you're not using a double boiler setup, be sure to watch the temperature of your melting wax carefully!
Gel wax melts slowly - higher heat will not really help it melt much quicker. Just let it slowly get to about 210-215°, stirring gently.
Once the gel is completely melted, you can add your fragrance oil. Most High Density Candle Gel (Buy Direct) will hold about 5% or 6% fragrance. So that means about 1 ounce of fragrance oil per pound of wax.
