I'm working from memory as I no longer have X1 installed.
Press Ctrl + A to select all. Then select Edit--->delete and when the options box opens deselect everything except track/buss automation. Click okay.
The part I'm not sure about is the Edit--->delete selection, in X2 it's Edit--->delete special but I don't think that option exists in X1 I'm fairly sure it's just delete.