A landlord will deal with breaches of covenant by serving what is know as a section 146 notice on his tenant.
This notice warns the tenant that they are in breach of the terms of the lease. It cannot be used if the tenant has not paid the rent.
It tells the tenant that it is your intention to forfeit the lease and gives the tenant time to fix the breach.
If the lease is a long residential lease Ask a lawyer for specific advice as your tenant may have additional rights.
After the notice is sent, the tenant is given reasonable time to put things right - how long you give them depends on the breach but it must be reasonable.
If the tenant does not remedy the breach within the specified time, you can then start court proceedings to forfeit the lease and get possession of your property.
As a landlord you can claim compensation and recover the cost of preparing and delivering this notice from the tenant - this is included in the notice.
If a tenant breaches any term of a private residential tenancy, you can take steps to have them evicted. You must provide the tenant with a notice to leave document and give them the right amount of notice, which is usually 28 days.