I don't think it is "as much force as necessary", but I did find a few things.
Edit again.
This seems to be on topic.
"There is also the Criminal Code of Canada, which is a federal law and applies in all provinces and territories, regardless of whether they have trespassing statutes of their own. It doesn't give property owners and security guards authority to arrest or prosecute persons for trespassing, or to exact monetary damages, but it does give them legal authority to physically remove trespassers. This power is found in section 41 of the Code, which says that a person in peaceable possession of a dwelling-house or real property (which is to say, everyone who owns or rents or has control over a home, or any land, or any buildings attached to land), or a person who is acting under his or her authority (such as a security guard), is allowed to use reasonable force to remove trespassers. So, if a person is trespassing on property and won't leave voluntarily, a guard would have legal justification under this section to use reasonable force to remove him or her."