How do i remove the plunger in bosch 1590 evs sabre saw

SOURCE: blade misalignment

The 1590, like several Bosch jigsaws, has a selector switch to choose the type of cutting action. You have to choose the appropriate cutting action, either straight or oscillating, to accommodate the material you cut and the blade you cut with. For instance, if using a very slender blade for clean curved cuts in wood, a slight oscillating motion ( setting II or III) reduces friction on the blade. 
If you choose the straight cutting action you get maximum accuracy, but drastically increase the friction because the blade is held firmly to the roller bearing.  A slender blade can handle that for brief periods, (say... less than thirty seconds) in soft, thin wood with a straight cut. In hard woods or engineered wood products ( plywood, MDF etc.) the thin blade will heat up and bend. 
You can reduce friction by choosing an oscillating cutting motion, or you can use a larger, sturdier blade. The "Aggressor" blades do not cut as smoothly as the "clean" blades, but they cut faster and are stronger. To cut thick wood ( 4x4 ) or a long cut in engineered material, that is the blade I use. Select number III or number II for 'type-of-cut' and use a bigger blade. See if that stops the "bucking."
Good luck!

SOURCE: My 9 month old Bosch 1590 jigsaw will not start??

The problem is the switch, or trigger switch. It may just have saw dust in it or it may be shot. Try blowing the dust out of it with a good blast of compressed air. If you don't have a compressor to do this go to a tire shop. They will help u.

SOURCE: how to attach 'plunge lock lever' to Bosch 1617

I have been repairing the Bosch tools for quite a few years and I still hate putting those levers on. Unfortunatly,there are no "tricks", you just have to set the spring in the lever then use a small screw driver to set the other end in its slot. Then try to rotate the whole thing untill the lever goes into the proper notch. It usually takes me 5 or 6 times to get it in, sometimes it goes in first time (rare). Sometimes I'm at it for 1/2 an hour.

Good Luck