1) Go on for the Hill Road











2) Just at half of the road you'll see an high tower, it's the Watch Tower











3) Climb it until you reach the top and the Achievement will pop up

1) Gain the access to the RESTRICT C Area using the Seargant Key











2) Go inside the bulding by the entrance on the right.











3) Go all the left, until you reach this room and see a long corridor going down











4) Go ALL down in this corridor, at the end you'll see a wall, touch it and the Achievement wll pop up

NOTE: "After the last patch you are not immortal anymore, so it's now possible die and commit a SUICIDE."
1) For this one simple reach the WATCH TOWER











2) Go on and reach the top, then jump down... well, guess what?











3) You "finally" (SUIC)DIE.