Do take note that under the law, the Landlord is NOT allowed to force himself into the property when the Tenant is still living there, or to illegal lock up the property or to change the lock, etc. That is trepassing. There has been a legal precedent on this, whereby, the Court has found the landlord guilty. The Landlord was advised by the judge to pursue the errant Tenant in the Court Of Law & not to take the law into his own hands.

The simple analogy would be like the relative of a murdered victim killing the alleged murderer. This relative will most probably have to face the gallows himself.

If your Tenant has not paid the rent, you have to get a court order to evict him. This will be a lengthy process.

Do take note that even if the Tenancy Agreement has a covenant allowing you to lock up your property, etc, it is in reality something that cannot be legally enforced under the law.

If you don't believe, just ask any lawyer.