Did you read the brumation article on this site yet? If not, do so ASAP.
Mine is less than a year old and decided to brumate a few weeks ago. I was worried at first, and thought something may be wrong (sleeping more and eating less) as they don't usually brumate at this young of age.
Well, finally one day she burried herself in the corner under the paper towels and I just cut some into big chunks and layed them over top of her. I kept the temps the same and light schedule the same. A week later I took her out to soak her so she did not get dehydrated. She woke right up and was alert. She soaked, poo'd, and has now been back on her regular schedule for the last week. So she brumated for only a week. They all do this differently.
I'd keep the temps regular. If she wants to sleep on the cool end, that is great. Mine slept on the warm end, but not under the lights and dug under the papers.
Then be sure you soak her once a week for about 20 mins (don't let her drown though!). Dry her off and put her back. If she wakes up and stays that way, great. If not, then let her go back to sleep and repeat next week.