My ageing macbook didn’t quite like the upgrade to Lion. Addittionally, the fact that rosetta is no longer supported is rather crucial when you have a specific piece of hardware that uses custom PowerPc software to run. Yes it may be old but, in my case, that would require replacement of a specific niche bit of hardware.
As long as you have a Snow leopard boot DVD and a time machine backup of your mac pre Lion installation, its actually quite easy.
On would assume you made a time machine backup just before upgrading to Lion?
Place the boot disc into the drive, restart and Press “C” during bootup to get the DVD to be the boot drive. Afterbooting up, before confirming a clean SL install it will prompt you for a restore from a time machine backup. Follow the instructions by reaching for the utilities tab in the menu’s.
After ensuring the time machine drive is connected you will be offered multiple restoration points. Luckily the version number of the OS is indicated. So choosing the last 10.6 version would have you selecting a snow leopard restore.
A few clicks further and a serious bit of a wait, and its all done.
She’s running much smoother again and I have my legacy apps.