Before you talk to your landlord, I would suggest reviewing your lease. Most leases require that all tenants be listed on the lease. Now, you have two tenants who have established residency in a property without the owners knowledge or consent.
In order for a property owner to rent out a property, it has to be listed and insured as a type of commercial property. When a tenant signs a lease, the lease should state whether the property is to be used as a residence or for business. If you signed a lease for a residential rental property, then technically, you have been making money from someone else's property without authorization. Depending on your state laws, and the terms of your lease, you, unfortunately, could possibly be held in breach of contract and held liable.
On the subject of eviction. I used to own a rental property. In the two instances that I had to have tenants evicted, I had to go to court, the eviction had to be court ordered, and the eviction notices were delivered by the sheriffs department, and then they had 30 days to vacate the property. In one of those cases, the tenants basically lived in my house for 5 months without paying rent, while my case went through the courts.
Hopefully, for your sake, your roommates will leave without much trouble, and you have an understanding landlord...

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