How do I replace Linux Mint with Kubuntu, while still having my UEFI Windows 10 boot?

Hello!! This is my first thread here.

Tried Kubuntu, and loved it, and would like to replace my Linux Mint with a clean install. I would like to do it without touching anything in my Windows 10 Boot.

When I go to manual install and check the partitions, I found that my ext4's mount point are not shown. One is supposed to be / and another is /home, which are my Mint's partitons

Here's a picture (sadly from my phone): https://app.box.com/s/8wgf3h9cvyz20ln3lpto42rvgwf8mn9c

How do I go about replacing my Linux Mint install, while still retaining Kubuntu?

Thanks!