Please check my answer to the post
However, if you want to completly replace the LPC assets by your own, some care must be taken (and because I have never tested it, it might just not work).
From the top of my head, the exporter code still has some 64 and 192 constants in it (so your assets should ideally 64x64 px).
Also the app assumes the LPC animations (idle, walk, slash, thrust, shoot, cast, hurt), so I fear that can be a big restriction to you.