Bosch uses a tool-less blade changing system for its jigsaws that it calls "Clic." The system makes changing blades fast and simple. Unlike the old days, you do not have to search around for an Allen key. Clean and sharp blades are less likely to bind, so it is worth investing in a few extras the next time you are at the hardware store. With the simple blade changing you get with the Bosch jigsaws, it is no problem to change out a dull blade.
Make sure the saw is unplugged or the battery is removed.
Insert the saw blade into the plunger until it latches into place. The teeth should face toward the front of the saw. The back of the blade should rest in the groove of the guide roller. The plunger and the guide roller are between the body of the saw and the plate.
Give the blade a yank to check that it is firmly seated. Plug the saw back in or replace the battery and proceed with the cut.
Practice removing the blade. Let the saw cool for a moment.
Hold the saw over a work bench and push the ejector lever to the centre of the front of the saw. There is a centre stop; you will feel it. The blade will eject and fall out.
If the blade will not go into the plunger, check the positioning of the slots in the blade. They should be at the top. Push the ejector lever and try again. From time to time, make sure the blade holder is tight.
Use protective gloves when handling blades. They can be sharp and hot.