Hi,
this is really easy and straight forward. Just shrink the Windows volume to that size that you have enough free for your Linux installation. Then download the MATE OS build for the P2 Max from here https://ubuntu-mate.org/download/ move it to a USB drive and boot from that drive. In the installation gui just create a new partition for the Linux OS. Donte use the auto setting is will shrink you’re Windows partition. After the installation choose the Linux as first boot option and then you will get asked if you want to boot Linux or Windows. If you choose Windows for the first boot option it will never ask you if you want to boot the Linux.
Greetings