You install Linux normally first and then install the surface kernel after. Until then you can't use the pen and touch is limited. You'll probably need at least 2 free usb slots on the surface though, one for the isntallation medium and one for an external keyboard. If you don't have a usb c dock, you'll need to figure out how to get a linux iso on a usb that includes the surface kernel, which is possible but fairly compicated compared to the usual installation.