In order to remove your current GPU, look for the PCI Cover located above the GPU to the back

Remove the two Screws holding the GPU in place

For Users with current Radeons: Remove the power connector from the board as shown in picture 2, you shouldn't need the PCI Power Adapter that you bought unless your GPU Uses 2 connectors

After removing the pci cover and the power connector (Radeon users), go ahead and pull the tab as shown in picture 3 away from your current GPU and lift out your GPU