Or you can just use god mode. For Lost Life, I recall that someone on ULMF posted a version with god mode enabled.
I'm surprised no one bothered doing that for The Demon's Stele, so I'm attaching my own modded version to this post. (This is just the main swf, so you need to stick it into the existing game directory). Among other things, god mode lets you adjust the princess's obedience & mood, and has hotkeys enabled for things like changing her arm position, increasing/decreasing your stamina meter, changing the number of hearts, etc. I forget what keys you have to press for each of those.
IIRC I added a few extra color variants for her underthings. Now it should have 12 total color settings for her underwear (the original six, plus a more see-through version of each), and six total colors for her stockings. At one point I tried editing the code to allow changing the color of her actual dress, but I gave up because it looked like crap and I couldn't understand why.
