First find a sucker, similar to a children's toy or a clothes hook with sucker function. It is easy to remove the aluminum gusset plate without causing any damage. Just put it on the table and drill it with an electric drill. Generally speaking, you don't need very professional tools, you can easily make holes with scissors. When the pipeline passes through, it will be better to spread a layer of sealant around the hole. When drilling, the force should be even to avoid damaging the aluminum plate with excessive force.
This drilling method is relatively simple and will not destroy the material. You can find the materials and test them yourself before work.