Mac users: how do I use custom images when uploading house to The Sims 3 Exchange?

[KateSterling]

I've uploaded homes to The Sims 3 Exchange in the past, but used the standard format.

I want to upload my file after changing out the standard auto-generated images with my own customized screenshots (the standard pictures really don't showcase one's creations).

I already know how to upload screenshots and edit them into 512 x 512 pixel, 72 dpi format. I just don't know how to replace the standard images with the edited screenshots before uploading my Sims3Pack to The Exchange.

I've been researching for some time and have found instructions for PC users. The problem is, I'm using an iMac.

Do you know how to do this using an iMac?

I really appreciate your help! :)

[HugeLunatic]

Well I've never uploaded to the Exchange so I have no idea how they modify the images. If you can tell me how it's done in Windows or link me to a tutorial I might be able to help find a way to do it in OS X.

[simsample]

Well I've never uploaded to the Exchange so I have no idea how they modify the images. If you can tell me how it's done in Windows or link me to a tutorial I might be able to help find a way to do it in OS X.
On PC most people seem to use this program:
http://www.zindasgoldensims.com/

[HugeLunatic]

Well that program runs straight from the exe file and doesn't install. It's possible it would run under Mono, have you tried that?

http://www.modthesims.info/showthread.php?t=366580