don't know what VSTi you are using ...so there could be other ways to go about this, but basically: let's say you have one drum... crash or whatever... and use ONLY the midi notes for that [mute the others or have the others on separate midi traks being sent to the VSTi and muted for the moment... OK so solo what you wan to hear then render and clk the box at bottom of render dialog to add the render to the project as a new track... name the rendered track rinse and repeat for all the drums you want... now you have wav files of each drum