I was wondering how long it would take to change somthing like this:

http://www.theanimegallery.com/image/28561

Into this:

http://www.theanimegallery.com/image/28562

Or:

http://www.theanimegallery.com/image/14799

To:

http://www.theanimegallery.com/image/28388

I was also wondering what would be best to use to actually do this?
I only have paint.net at the moment, though I can work with gimp, can't really get photoshop unless I download it.

All answers will be great thatnks for you time guys and gals.
NTB-

I have no idea how those were done, by my guess is that the author either had vectors/scans of the two options (fully clothed, barely clothed) and just did the wallpapers or he had the barely clothed ones and then put clothes on it... I wouldn't know how to remove all those clothes and create something that would look remotely close to proportionate...

If you are not VERY good at photoshopping images and drawing, I wouldn't even try it, seems really hard and complex.

ya the people on 4chan use photoshop mainly....there is a way to take off clothes. not sure about putting others on but its probably the same method. im not too good with it myself.

You would have to do it all by hand using Photoshop, if you cant already make something like that, then you cant take off there clothes. You would have to make the legs body and everything so it like making a new person.

Moved this over to the "Current image projects" category...

Yeah bud Photoshop would be the best program to use for that. Mainly because it would drastically decrease the amount of time you would put into the image then like let's say: Gimp or Paint. You may have to bite the bullet on this one and get PS, or get some back wraps, coffee, and start remaking the image on Paint or Gimp. Sorry bud?

I don't think that it is possible to 'create' those types of things on any program at all. I believe that Konata and IGC had it right. The artist did two separate 'versions' of the same picture. You can't simply swap things around or anything. It would be like scanning in a picture of the Mona Lisa and putting an Afro puff on her head...
When an artists scans in pencils, he can color the work however he chooses. If he is using a tablet, he can change it as well, in the early stages, especially if the original had no clothes. A finished jpg however cannot be altered in this way. You can't take those images as they are and do that kind of thing to them like the artist did. You would need the separate layers, or 'vectors' groups of each part .
Am I making any sense or is that a lot of gibberish??? I can't tell.

If you had a tablet and a few hours to burn you could redo the image on Photoshop I do it all the time. You can do anything on Photoshop man don't underestimate the power of Adobe!