You can run ME2 bypassing your Origin library. Just open texmod.exe and go straight to the install folder to open ME2Game.exe (not MassEffect2.exe)
Well, now (technically hours ago, but it still applies at the moment) I feel like an idiot... That was the check I needed for running the .tpf as well.
If you want to read about my perilous journey, do continue after this paragraph. If not, just read the following part: I swapped both extractable dancer outfit textures with Kelly's normal uniform confirmed main texture and it created a seamless outfit... but it's quite different in multiple areas from her actual normal outfit xD
I figure the game (any modern game most probably) is told where to find each piece they need: gloves, sleeves, upper part of the outfit, etc. I also figured the normal map was the one telling them this (or at least how to fold), but I guess I either did something wrong or need to change something that I don't know how to find, which is the 'put this piece there' 'thing' or file. I would think people don't have issues with this because they change the original textures, rather than outright replace them with another one with differen positions on the texture for hands, legs, back, etc. Did I mention I have no idea how this all works?
Read on for my multiple experiments that were in the end fruitless in getting any closer to Kelly's outfit. It's almost as if... Kelly's dancer model isn't her body (which if I think about it for two seconds, wouldn't be all too surprising). That or I somehow extracted an unknown texture, which I triple checked: it's the same texture all the female crew members use.
Now after I read your post and used your links (I can't say I understand all of it), I managed to get Mass Effect 2 to swap two textures of the dancer outfit for Kelly's normal outfit, BUT it results in a weird semi-transparent shiny hybrid. (Of note is that both normal uniform textures or maps are 512x512 and the dancer outfit textures or maps I managed to get are 512x512 and 256x256)
Extra note: I first tried all this with .DDS before letting texmod save .JPG's so I could see them. Using .JPG's might ruin the alpha channel (which I figure might be causing this mess), though as I said, I used .DDS first with only the (seemingly to me at least) primary textures (the diffuse ones, I'm guessing), had one swap out for the other and it produced the weird hybrid that I'm still stuck with while using two replacing textures (though yes the second one should normally not matter nearly as much as the first, they still overlap instead of the old ones going away).
I repeatedly failed to to extract two other textures or maps, one for each outfit, which by the look of it are the normal maps purpleish and blue), which are apparently indeed hard to extract from the game. I don't own Photoshop and I have no idea how to make a normal map or modify one, though I suppose if I could get the number of the dancer outfit's normal map and the actual normal map of Kelly's normal outfit, I might get this fixed, assuming not swapping out the normal map is the main problem.
I've been at this for hours and I'm not sure screenshotting the normal map and cutting it down and swapping one for the other is going to fix this shiny hybrid and I'm guessing I did something stupid again, though I can't figure out what, since most tutorials talk about modifying an existing texture and swapping it out instead of using another texture. I figure Kelly's dancer outfit having heels and her normal uniform not having those and the dancer outfit being shiny 'should' cause problems in the first place.
Update:- I noticed it was strange there would be Cerberus symbols on the back of her hands... Resized the normal uniform's texture that replaced the smaller one (256x256) so it would be the same. Didn't do anything though.
- Changed which texture was swapped with a uniform one. Hardly a change, so the second one is probably mostly for accents... I could probably just stick to one texture being swapped, excluding the red-green one from Kelly's normal uniform.
- Next up, figuring out if I simply forgot to swap out her skin areas, though for the non-head stuff I thought they were included in the outfit textures, rather than put somewhere separately... Ah heck, they are. Explains only one male and one female outfit for crew members with all skin colors... And, which I didn't know yet, the blue skin zones for the asari come from the model or texture underneath and don't come from themselves. Must be that grayscales stuff. Hm, so does that mean I have to track down the skin textures of the hands, neckline and err, legs? Then again, the normal uniform appeared semi-transparent over the dancer outfit anyway... Then again there were the Cerberus symbols... NOPE, no skin textures found for hands, arms, legs or chest (that light up green when the outfit doesn't anyway).
- There is the strange texture that is left that is a rectangular black bow with orange stripes, which might help with marking the uniform a bit more but for the rest, beats me:(
- FINAL check: The dancers at Omega wear the exact same euh, 'creation' of mine. So... what now? I'm guessing the normal map (and/or another map) is what I need. Time to try to cut it out of a screenshot I guess... Ah, had the dancer outfit normal map (confirmed) swap out with the normal uniform. Didn't do anything:(