activated

Someone bumped me in the rear the other day. It activated the headrest. They pop apart and the front jumps forward about 3 inches to help reduce whiplash. Is there a trick to putting them back together? Is it a dealer fix only. Anyone done this?

I purchased my Genesis on Oct 24th and the 3 month XM radio free trial was expired on Oct 30th. I asked Hyundai about this and they told me that the warranty has been activated in July. XM radio free trial starts when the warranty is activated and that was why XM radio free trial was expired...