The only way to go from one OS to a previous one is with a re-install ...
Did you think you could just over-write Lion with Snow Leopard ??
I don't agree with your comment at all, Lion is a new OS and the biggest thing dropped is support for older PPC applications that require Rosetta translation. If you use these then you shouldn't have upgraded in the first place really.
Let me tell you this . I have a brand new Mac book pro that came with Lion . After the recent update , nothing worked . This is my first laptop and I made a giant leap from 10.3.9 panther to lion . I expected major changes , but I can honestly say that lion is the most convoluted pile of crap I have ever seen , nothing works well or efficiently . I went to the genius bar at my local Apple store to get it running again . After talking to the tech , and reading complaints ( many I share ) about lion in general , I had him install snow leopard ............... I'm very happy with it . I would recommend going back to snow leopard as soon as you can because Apple really dropped the ball with Lion ................. versions ? I don't think so ....... I want save as .........its not old fashion , its fast and needed for productivity , especially if you work with graphic files and documentation . Lion is junk , yeah it looks nice ......... that's about it .
I am always getting told off on this site when I ask questions.
Hang on in there Daggilaar. Ignore the rude people.
To answer your question, my step-by-step suggestions would be:
1. make a complete bootable clone of your hard drive, as it is now (i.e. with Lion). This clone should be on an external FireWire hard drive. If you haven't got one, get one now. Its size should be at least the same size as the internal HD in your computer + at least another 10% or so. It might be wise to avoid Western Digital but all other brands are fine. You can make the clone using Carbon Copy Cloner (which is free).
2. Test the clone by booting your computer from the external hard drive.
3. Use the Disk Utility application on your Snow Leopard disk to reformat the hard drive in your computer.
4. Install Snow Leopard.
5. Migrate all your stuff over from the external hard drive.
This will take a while but hey - you get Snow Leopard back !
Well there is an alternative to to wiping your drive and starting over. If , like me Lion is presenting you with some issues then you could consider setting up a Bootcamp partition and instaling Snow Leopard on that. My intention is to do this and slowly migrate my files from one to the other, expanding the partition ratio as I go.
If and when the developers of the applications I am using that are not fully Lion compatible catch up AND Apple iron out the bugs in the OS I could return to the Lion partition and reverse the procces.
Yes you can go back to Snow Leopard same thing i did Lion is having some bugs. step to step guide:
1) Make a Time Machine back-up (Put pictures,movies and music on the harddrive manualy)
2) put the Snow Leopard disc in your Mac then wipe your Mac's harddrive
3) Now you can instal OSX Snow Leopard (50 min)
4) Restore proggams manualy in Snow Leopard from Time Machine.
If you set back a Time Machine back-up it restores the OS version at well
Hope you Enjoy Mac OS X Snow Leopard!
Snow Leopard does only get security updates no new content
There is a great many posts on how to achieve this already here on the forums. Try doing a bit of searching if you are all ready committed to returning to SL. Most try to update software or learn how to use or disable certain Lion features. In six months SL will be two OSs behind with no further support. So search for one method of returning to SL that suits you.