Removing doorknob of keyless lock

[jzmk]

Hello,

I never tried to do anything like this and I hope this community can help me. I share a bathroom with someone and the bathroom door can be locked from the inside but there is a way to open from the outside with your fingernail. I want to know how i can remove the doorknob from the inside so that if i lock the bathroom with my fingernail from the outside (inside of my room) there is no way to come in. Here are some pictures:
Inside the bathroom



Outside the bathroom

[Squelchtone]

[EDIT: Moved from Locks (where we talk about picking different brands of locks) to This Old Lock (where we help the public with lock problems they are having)]

[jimu57]

That would cause a problem if you went to the bathroom and shut the door. Wouldn't it?

[Robotnik]

I'm presuming this is a Jack-and-Jill type bathroom, with one door into it from the hall and another from your room, and you're looking to control access from the bathroom into your room. Am I reading that right?

If so, removing the inner lever of the privacy leverset isn't going to accomplish what you're trying to do. Door can still be easily opened. I don't know the specifics of your situation, or whether the property is rented or owned, etc, but a couple ways to prevent entry into your room from the bathroom could be:

Cheap, Relatively Non-Damaging Option: Install a simple slide bolt (like a small gate or cabinet latch) on the inside of your room. Lever will still operate (and could be privacy-locked from inside the bathroom), but door won't open unless you've thrown the bolt. Easily filled and touch up painted upon move out.

More Expensive, Property-Altering Option: Install a deadbolt with the keyed side facing into the bathroom, thumbturn on your side.