run script for polymer cross-linking, xtd and xsd problem

hello,

I am using xlink script to perform an epoxy cross linking simulation. The input structure of the script must be in xsd format but after using the Amorphous Cell module to generate the proper initial structure consisting of the monomer DGEBA and the curing agent TETA, the prepared structure has an xtd extension.

firstly, how can I change xtd into xsd?

secondly, when I try running the script from the script interface I get an error saying the job is failed and I believe it is because my input file is xtd instead of xsd. but when I try to run from the User Menu following the below instructions given in the usage guide:

1)Import the script into a Materials Studio project
2)Open Tools | Scripting | Library and add it to your My Favorites library
3)In the User Menu tab of the same dialog, click Import and select “User Menu.xml” in the file
browser
4)With an appropriately prepared structure open, select User | Simulate | Crosslink to open the
user interface

Following these structures, I do not get any errors,s and the script runs but my prepared structure is still in xtd format and I do not know how this script is running. 

I would appreciate some clarification.