So you're stranded in low Kerbal orbit (LKO) and Kerbalkind is too lazy to send you a proper rescue rocket? Instead they send a probe which whizzes by you and tells you you have to get down on your own. WTF? You're gonna burn up in the atmosphere! And if you don't, you're gonna die on impact! But what if I told you some BadS didn't burn up and survived impact? It's gonna hurt, but would you rather stay in orbit? Your choice. Here's how it works.
Go on EVA, activate your jetpack with R and go to a really low Kerbal orbit. 70.5ish km. Circular. Prograde. If it's retrograde (or heavily inclined), forget it. Burn 3.1 units EVA fuel retrograde. That will make you turn oddly, so stop thrusting during that turn. Now wait and pray. There you go, you deorbited without burning up.
But now the ground/water is coming closer. Throw your chute to increase your area and drag to slow down. No chute? Don't go feet first. Turn your body to maximize your cross section. Use left mouse button (LMB) and drag to do assume a horizontal attitude. There, you can feel high g-forces as you slow down. But the ground is still coming closer at frightening speed. Fortunately, the atmosphere gets thicker as you descend and if your impact point is low enough, you'll wake up from a short coma alive.
If you start your deorbit burn shortly after flying over the peninsula before the KSC, you'll come down close to the KSC. If you come down too early, you can assume Superman attitude (fly head first) to fly a little farther.