Applying custom stroke styles in PS
Double-click on the layer you want to apply it to, which opens up 'Layer Style'.
Click on the 'Styles' tab at the top left and then the cog to 'Load Styles...' and open up the .asl file. I've gone ahead and applied the most realistic stroke settings as a starter, but of course you're free to create your own! Change them up. Save new styles on top of those ones if you feel the need.
TIP: if you have applied edits to the originals or created new styles, make sure you save them by clicking that cog again and selecting 'Save Styles...' (save over the old file if you want) before you close Photoshop.
Play around with the various Contour styles (2) as you can create some really interesting effects. Fiddle with the Shading section too (1) and adjust the levels to your liking. There's also the option of adding texture.