An eviction is a lawsuit where the landlord sues the tenant for possession of the unit. You would/could only file an eviction lawsuit if the tenants were violating their lease (such as not paying the rent), not because their rent is too low.
Your options will depend on a lot of factors, the main one being the lease. If the lease is for a specified term (and there is time left on the term of the leases, meaning the lease expires at some point in the future), then you generally have to either honor the remainder of the lease, or negotiate to buy the tenant out of their lease. You do not have any grounds for an eviction unless the tenant is in violation of their lease contract. You can give them a notice of non-renewal letting them know their lease will not be renewed after it expires. This is not an eviction, it's a non-renewal.
If the tenants are month to month (either their lease specifically states they are on a month to month tenancy, or their original lease has expired and they remained in the unit on a month to month basis, or they had no written lease in the first place), then you can terminate their lease or raise their rent with proper notice (proper notice will be defined by state law, and/or the original lease). This is not an eviction. It's a termination of their month to month tenancy.
In either of the cases above (non-renewal or termination), you would only have a need (and grounds) to evict the tenant if they refuse to leave after their lease expires or is terminated. This is referred to as a holdover eviction: http://www.evicttv.com/episode...
Eviction lawsuits can be costly and take a long time (especially in California), another option that is often faster and cheaper is Cash for Keys: http://www.evicttv.com/quick-t...