How do I convert a person to the idea that Private Property is bad ?

What I mean is many Americans think Capitalism is good because it allows
Private Property but
Private Property rights are only for the Rich/Wealthy Capitalists is this right Private Property is personal ownership of Property we need common ownership or collective ownership of the means of production.

Who owns the means of production?

One of the central questions of any political ideology is "Who should own and control the means the production?" (Means of production refers to factories, farmlands, machinery, office space, etc.) Generally there have been three approaches to this issue. The first was aristocracy, in which a ruling elite owned the land and productive wealth, and peasants and serfs had to obey their orders in return for their livelihood. The second is capitalism, which disbanded the ruling elite and allows a much broader range of private individuals to own the means of production. However, this ownership is limited to those who can afford to buy productive wealth; nearly all workers are excluded.

http://www.huppi.com/kangaroo/L-socialism.htm

Im trying to convert members of Trade Unions that I know from supporting the Democrats to supporting Marxism.

farmland being used for biofuel production while millions starve.

I'm convinced that the means of economic production and distribution should be commonly owned, but I don't see why people shouldn't own their own homes.

So I can crash on your couch whenever

Nev.

I'm also quite curious about this myself. My gf told me today that she wants to get a high paying job, own her own business, make a lot of money,have a nice car, and all the rest of the capitalist dream. This made me scream inside but I kept cool and just laughed and called her cute. I don't want to scare her away by going full blast against this and stuff but how do I slowly over time pull her to the revolutionary left?

Well bringing her to the RevLeft would take a lot of time, I'd say your priority should be showing her that things are just things, and no amount of things can bring you happiness, only your friends, family, and freedoms can do that. I've been doing the same thing with my friends and family. I see so-and-so wearing glitter, and I say "hey, did you know that some of that glitter came from slave labor in India? They force children to mine the minerals that glitter..." bla bla bla, some sweatshop facts and all that. Just sort of plant the seeds. Just do what ever you think would work man, good luck.

http://youtu.be/DHM758QvcEs

Edit:
I'm bad about getting off topic. And embedding YouTube videos -_-

Owing land is like keeping the Earth hostage. Have you ever seen some of the bourgeoisie mansions? Some of them are 3 stories, have dozens of rooms, and acres of idle land that is generally kept up for pure aesthetics reasons. First off, does a medium-sized family really need that much space? No, they don't. And what about all that idle land? Imagine if you built a clinic, or used that for farming, or what ever. It's pathetic.

I find this pretty persuasive:
You are horrified at our intending to do away with private property. But in your existing society, private property is already done away with for nine-tenths of the population; its existence for the few is solely due to its non-existence in the hands of those nine-tenths. You reproach us, therefore, with intending to do away with a form of property, the necessary condition for whose existence is the non-existence of any property for the immense majority of society.

First of all, don't think of it as 'converting'. That just makes what you're doing sound similar to those guys in white shirts coming to one's door and saying "Let me still you about Jesus". One, it's going to come across as preachy. Avoid that, you want to appeal to people on their level, not from a place of perceived superiority. Secondly, don't look at it as something that needs to be accomplished in one sitting. Very rarely are you going to be able to convince someone that private property is a "bad thing" in one conversation, especially in this political and economic climate. It takes time; all you should try to do is sow the idea that private property goes against the good and welfare of the majority of people. Build people up to the idea, don't go on an all out rant about the dismantlement of private capital and the basics of public/collective ownership. Simply impress upon whoever happens to be listening to you that private property doesn't translate into actual ownership for the vast majority of society, and that the reality is a minority (who happen to be the financial-political elite) are the ones who own the essential goods and livelihoods that most people rely on. Explain why this is, but do so at a pace comfortable to both yourself and the person(s) involved.

You've got to teach them that 'Private Property' doesn't mean their stuff, it means the means of production e.g. factories, natural resources, farmland.

So many people think that they wouldn't own anything under Communism, it really is stupid.

Well, yeah my intention with the Communist Manifesto quote was not that you should whip out your pocket Manifesto and start reciting, but rather use the arguments.

I'm aware of that...

Hey, just setting the record straight.

No worries. :)