Setting up an ubuntu server

Hi everyone,

I've been struggling lately to set up my ubuntu server. My computer that I've had for years now is equipped with Windows 10 alongside with Ubuntu Desktop. Both main partitions are approximately evenly split. But recently I've been working on my laptop more and I would like to use my computer as a server because I think I could get a lot more work done that way. Unfortunately, trying to install Ubuntu server, I can't seem to find a step where I can repartition my drives myself. I would like to completely erase Ubuntu desktop and use the same space for Ubuntu Server - And of course keep Windows 10 (for reasons).

Now I know that you can "transform" your Ubuntu Desktop to a server, but I would like to go with a fresh intall to clean it up. I've been installing a billion packages and I would like to clean it up you know what I mean.

So is there a trick to install Ubuntu Server (here I'm willing to install the latest 18.04 release) on a specific partition and not overwrite my whole drive ?

Thanks in advance