change fixed width help

i am well aware of how to change the width of the new 2.0 basic red template as per the info here in the knowledge base:

[url]CS-Cart Documentation — CS-Cart 4.15.x documentation

the problem i have is they assume a width that is toooo large for the 800x600 users

i am very aware of css and how to reverse engineer the hundreds of lines of code to find all the css that i need to change.

but if anyone has already found the lines it would greatly save me the time and headache of this, so i can move on with my upgrade from the 1.35 site to the new 2.0 one

i am trying to set the width to 768px fixed width on th ebasic red template, i have made the changes already to set as fixed width as per the kb article, now i just need the info on changing it to 768px

thanks for the help in advanced