Subset and Analyze
In Windows Explorer Go to C: and then go to Program Files\arcgis\Utilities and double-click on AdvancedArcMapSettings.exe.
This will open a dialog box where you can change this value. Click on the GeoStatistical tab and type in a Maximum # like 90000 or something like that. Click Apply and then close the window.
Subset the data
Close everything but ArcMap. Under the Tools pulldown menu (located along the top row of options in ArcMap) go to Extensions. In the Extensions dialog box check on Geostatistical Analyst. With the cavalues shapefile highlighted, go to the Geostatistical Analyst pulldown button and choose Create Subset. In the first window that opens, 'cavalues' should be entered as the Input Layer you want to subset. Click Next. In the next window you need to move the slider over until you have a 70% training sample and therefore a 30% testing sample. You could choose more but it will take longer (a lot longer) to run the analysis. This will produce two new datasets contained in a geodatabase. Click Finish and ArcGIS will randomly subset the polygon shapefile. This could take a while, so be patient. After it is done a window will open asking you if you want to add the new dataset to the layout, click Yes.
Drew
We don't use AdvancedArcMapSettings.exe (for Geostats) in ArcGIS 10.x anymore. I'm also not sure why you would need to do what you outline, where did you get the instructions from?
To subset the data please search for the SubsetFeatures tool.
Regards
Steve