How install qubes 50% and pure is 50%

I’m not sure- I have a librem 13 v4- what procedure is recommended? Ideally qubes running on 60% current machine and pure os on other half. Currently pure os is on pretty much all of it.

So, how to change the partition, install a working qubes, etc, so can choose to boot on qubes or pure os etc

I’m not terribly techy so a step by step would be really helpful - can you help?

Thank you so much in advance