overwrite linux with lubuntu

[james226]

hi all. I'm just downloaded the iso of lubuntu and want to install it alongside windows 10 but heres the deal.
I got windows 10 and another Linux system with dual boot.. what I want to do is to overwrite the Linux system I have with lubuntu
and still be able to dual boot to windows 10.in the lubuntu installer I didn't see option to overwrite the second partition [only the first as the first is windows 10 and I dont want it].
tnx in advance

[oldfred]

You still have to make sure fast start up in Windows is off.

Then you should be able to use Something Else install option. If you just want same partition as / (root) choose that and change button. You select ext4 and / . If you have swap already it will find it and just install to that partition.

Lots of detail, screenshots and essential info.14.04 Something Else example
http://www.dedoimedo.com/computers/ubuntu-14-04-install-guide.html