I think I have confessed elsewhere that the only way I was able to complete this unfortunate project was to cheat by using solder mask. This allows you to spread solder paste only on the pad areas, and capillary action will actually pull the piece in to place as the paste melts in an over or over a hot plate. It is quite a thing to witness.
There are two ways to get a stencil. Once is to use a laser cutter. Most of us, including me, do not have a laser cutter in our garage. You may have a friend or Maker Space you can use. Most laser use SVG files, which you can find in the files section.
For the rest of us pour unfortunate souls, you can cast your mercy on someone like OSH Stencils, who will take your money to easy your misery. The gerber plot file is also in the files section. I would use a 3mil polyimide and 0.75" boarder. This should cost your about $5.00.
[Update] OSH Stencils has provide a link for ordering.