How do you install Kali Linux on a laptop?

Ja
3

Ubuntu is on it at the moment, but would rather experiment with Kali, the laptop is not my main device.

Ev

You can also use Kali Linux as a live version, this distribution is also intended for this -

or as a dual .Boot next to Ubuntu.

or in a virtual machine.

You slide the Kali DVD into the laptop and let it start with the DVD. Then you have several options to choose from.

Ja

I don't have a DVD drive or a stick that is big enough. How can I use kali as my main boat? I probably don't have enough memory for ubuntu + kali, so I just wanted kali

Li

With a DVD
With a CD (provided you use / build a minimal installation system)
With a USB stick
With a TFTP server via PXE boot
By hanging the hard drive on another box and phase 1 of the installation e.g. Execute using QEMU on this plate
With a floppy disk that contains a boot loader, minimal kernel and everything else that is necessary to load the actual installation system into a RAM disk via HTTP and execute it using kexec
With an external hard drive (same procedure as with the stick)
etc…