Inspect the floor area directly next to the door jamb. Clear away any debris so you're left with a clean and flat surface.
Place a scrap piece of laminate flooring flat on the floor and directly up against the front of the door jamb. You'll want the scrap piece to be at least six inches long. If you don't have any scraps that long, cut off the end of one of the unused laminate flooring planks.
Place the jamb saw on top of the laminate flooring so it rests flat with the teeth of the saw up against the jamb. Press down on the laminate with one hand to hold it in place and, with the other hand, slowly pull forward and back on the handle of the jamb saw until you have completely cut through that side of the jamb. Repeat this process on the back and middle areas of the door jamb until you have completely cut through it and can remove the cut piece of jamb.
Place the scrap piece of laminate flooring up against the baseboard and use the jamb saw to cut the baseboard directly next to the jamb. You'll need to cut two inches into that section of baseboard and then wedge a chisel along the cut line and break out that piece of wood.