Hi tvegas99,
I sympathise, I'm a beginner with the Kemper also, and whilst experienced with a wide range of guitar technology, I haven't found it immediately intuitive on how to get things done (undoubtedly because there is a lot of power to be harnessed). The secret to unlocking Performance mode is to understand that your most important control is the "Browse" dial. Use the cursor buttons around the Rig area to select your slot, and then twist the Browse dial - this will bring up a selection Menu to overwrite the current slot with another rig. The soft keys above the display will also give you an option to Delete a slot,
Big smiles,
Andy.