once you had edited the card, open mod in penumbra windows, then click "advanced editing"! in the new opened windows, open "textures" tab;
then click on a little folder icon on the left side where it says "input texture";
choose your edited card and click OK. after thatn, on right side of the windows, click "save as TEX" and save it in this very folder with any name you want!
now, go to "file redirections" tab and click "reload files" on the upper side! 
cool, now you should see your new saved file as red at the very top (scroll to find it, if its not on the very top)!
now, at the top right, select "DIY card" option WITH NUMBER OF CARD YOU WANT TO USE!!
on your red file, click or text box that says "add new path" and paste " chara/monster/m8058/obj/body/b0001/texture/v01_unknown_c_d.tex " into the text box!
click "apply changes" on top!
thats it! dont foget to tick edited option inside mod settings and click redraw all (or re-summon cushion)