How can I change the standard .jft .bjt .dio .cap files in LT spice XVII
There are now two folders, one is the standard folder at  

..\\LTC\LTspiceXVII\lib\cmp


The other folder is in (on a windows machine)

..\\My Documents\LTspiceXVII\lib\cmp


if you change standard.jft (or  .jft .bjt .dio .cap) at the above location it will be reflected in the drop down menu.