if you mean what I think you mean, then yes, you cut the parts with a fine saw blade, if they have a large pour stub to remove, just saw away a large part of it, until you get the hang of this,,and then sand the part like you would a vacuform part,,,,,as you sand, the resin around the part gets thinner and thinner, and about when it is paper thin, it comes off at the line where the "right size" of the part is
sanding is the same, also, wet sand your parts to float the resin plastic bits away, to avoid scratching, just as you would plastic,,,,,,one thing different, you don't have to worry as much about heat buildup ruining parts, so you can sand a little longer before letting the part cool
you don't want to touch your face or breathe in the resin dust particles,,,,,so, wet-sand, use a mask,,,,whatever makes you feel you are not breathing in the dust,,,,,,,that is not really a just resin thing,,,,,,styrene dust would build up in your lungs also