Yeah, right.. like you know how to do brain surgery on Extraterrestrial being from other stars or maybe even galaxies... Still, it's probably a good idea to sterlize the wound with povidone iodide solution and check cat scans and xrays one more time before entering the brain. In humans you never had to anesthetize the brain because it does not contain any pain receptors. Only the skin needs to be anesthetized.
Bleeding blood vessels are sealed with an electric cauterizing scalpel. "This is remarkable," you think to yourself. In Humans this kind of bleeding is almost always fatal. Gently separating the folds of the Extraterrestrial brain you find your way to a fragment of.. what is it??? It looks like metal but is extremely lightweight. It glows / flickers with a bright blue light. As you exit from the wound you wonder what the blue fragment is and who these Extraterrestrial beings are...
The wound is then closed with dissolving sutures.