Switching from Mint 15, need partitioning help

[loonsailor]

I have a dual boot system (Windows, Mint). I want to keep the Windows partition, and replace Mint with Ubuntu, but I'm confused by what I see in the installation process.

I'm running 14.10 from a DVD, doing the install, and get to the partitioning screen. I select "something else", because I don't want to keep Mint, but do want to keep Windows. The next screen shows me that I have four partitions on /dev/sda.

/dev/sda1 115GB NTFS Windows
/dev/sda6 260GB ext4 Mint
/dev/sda7 256GB ext4 Mint
/dev/sda5 7GB swap

I have no idea why there are two separate, equally large Mint partitions. When I boot Mint back up, I see that it's using /dev/sda7 on /, and not mounting /dev/sda6 at all. When I mount it and have a look, it's another entire root file system. Maybe some Mint update did this, and I never realized it until now.

Anyway, I think that what I want is to merge sda6 and sda7, and put ubuntu there, keeping sda5 as ubuntu's swap. Is that reasonable? If so, how do I do it? It seems I could delete sda7, make sda6 bigger to absorb the freed up space and change it from Mint to just ext4, mounted as /, and check the format box. Is that right?

Thanks for any help!

[egeezer]

Easiest way: delete sda 6 and sda7, click for New partition, format it ext4, and specify mount point /. I've done it that way many times, have never had it go bad.

Note: edit it / (the /. made it look like something elaborate!)

[loonsailor]

Thanks, egeezer!