Just as chiefkp said. And you'll be fine, no worries. I had to do a few, "grind 'em till you find 'em" before I discovered the perfect speed to be rolling at to engage 4L.
Just a tip: If you are off-roading and "think" you may need 4L in the future, best to go ahead and engage it while you can, before you are stuck and cannot get the momentum to engage it.
Welcome to JeepForum and Jeep in general!
2008 2-dr Rubicon, auto,
RK 2.5" Max Travel lift, Fox 2.0 shocks, 37" Nittos, 5.38 gears, River Raider skids, Warn VR8000-S.
RIPP Gen 2 Stg 2 Supercharger.
Bunch of other junk.