downgrading Nvidia driver 12.04

[Curt Tresenriter]

I've installed the final Beta version of Pangolin and am having the same 
old problems with the new nvidia driver. Unfortunately the 173 version 
is no longer a choice (so far) in additional drivers' so I've removed 
the new driver and booted to the 'recovery choice' to run the script 
from nvidia to install the driver I need.
Although mount command shows both root and home partitions mounted I 
cannot seem to cd to /home to get to Downloads to run the script (where 
it has been saved).

I'm not altogether sure this is the proper course of action as I've 
found many tutorials to downgrade the driver but they are rather old and 
so I'm trying what I've known to work in the past.

So, first question, is this what I want to do to get the 173 version 
installed? ...and question 2, how do I get the the Download dir to run 
the script?

If there's a better way I'd appreciate someone pointing me to a proper 
explanation.

Thanks