You have to give this subtenant 30 days notice of termination of tenancy and then file to evict them. Do not change the locks (unless you give this tenant a key) or you can be sued for forcible detainer.
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This sublessee is a tenant, and you have to evict them through the legal process, with a 3 day notice to pay or quit, then a UD suit, and not use self-help by locking them out. Maybe they'll just leave also, if you ask them to.
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