Install 12.04 on top of existing Linux Mint installation

This question has been answered before in many places but I just need some confirmation with my specific setup. I have Linux Mint installed and I just want a fresh Ubuntu 12.04 install to completely replace Mint. It's dual booted with Windows 7 and I want that to remain completely in tact.

Anyway, I'm currently running the Live CD installer. I've said I want to specify my own partitions and I'm at the following screen:

The list at the bottom expanded:

I confused by all the different partitions. Seems like I should just check the box beside sda5. But what about sda6? Do I just leave that alone?

Also just for confirmation, is the "right" way to replace Mint, or should I be deleting it first?

First, backup your /home folder. Once you format sda5 your home folder will be lost. All traces of Mint will be also gone, so there is no need to delete it first.

You can check the box next to sda5. It should be formatted ext4 and the mount point should be "/" (without quotes).

You can leave the swap partition alone. It is used as virtual memory and hibernation. Nothing permanent is stored there. Ubuntu will use it just like Mint.

The boot loader (GRUB) should be installed in sda (not sda1).

Hope this helps