The BEST way is to make another batch and chill it right into the primary. It'll be fermenting within hours.
Alternately, you can save some in a sanitized jar and use it later.
there are a lot of threads here on the subject. Try a search.
Oh don't give me none more of that Old Janx Spirit
No, don't you give me none more of that Old Janx Spirit
For my head will fly, my tongue will lie, my eyes will fry and I may die
Won't you pour me one more of that sinful Old Janx Spirit