There are regular openings in the co-op when members leave town for a few months. Subleasing involves taking on all of the responsibilities of a member (cooking, cleaning, & attending meetings). If you intend to sublet for 3 months or less, you do not need to complete the full membershipping process. The timing of the sublet is dependent on how long the member will be out of town, but typically sublets are available over the summer or for 6 month periods. All specific arrangements will be between the member holding the lease of the room and the subletter.
Please check out each house for availability notices.