Here are the instructions and video for your convenience.
- Unplug the power from the jigsaw, always follow the safety instructions in your product's manual
- Insert the jigsaw blade using the FastFix mechanism
- While holding the blade, carefully pull down on the blade to bring it to the lowest point in the pendulum action
- Move the pendulum setting to its #3 setting which is closest to the front of the saw
- Remove the wrench from the rear of the jigsaw base plate
- Using the wrench, tighten the hex nut in a clockwise direction until it is fully tightened against the blade
- While pushing gently against the blade with your thumb, use the wrench in a counter-clockwise direction to loosen the hex nut until the blade slips free from the carbide jaws
This will give set tension on the jaws which will minimize deflection and also minimize wear on the blade.