thin out the bedding till you get the temp on top you want. You can put the Probe in-between the uth and glass or directly on the UTH. Using tape or hot glue to secure the probe so it dont come off.

Set the thermostat to the temp you want, and let it warm up till you get the temps inside. Glass is the hottest point in the tank the snake can get to so that needs to be your main focus. Once temp is achieved work on bedding thickness to fine tune it.