How do I remove the PCIE brackets at the back of a case?

How do I remove the PCIE brackets at the back of a case? pcie slot bracket Lenovo Pcie Riser, 4 Slot Bracket Only No Green Board 01Cx969 Distributor of Lenovo products Same-day shipment pcie 50 slot Chassis must have at least 6 PCIe slots and be installed as seen above The bracket cannot be properly installed if a solid, metallic strip is above the PCIe

pcie 50 slot connector slot near the Bracket end of the gold plated fingers whereas the 5Volt 32Bit PCI bus has the polarising slot furthest away from the bracket

pcie slot cover PCI Rear Slot Cover for all circular power connectors This PCI bracket allows easy connection for the AC adapter in legacy systems Just insert this PCI InLine® PCI PCI-E ISA Extension Card Slot Bracket 6 pcs InLine® bracket allows closing the free slots on the back plane panel of a caseserver Blind