You can download EJS source and open it with EJs,
or download jar file , double click to run it, right click then select open ejs model.

What you need to modify is "[b]Fixed relation[/b]" Page: you will fins the following line

mat3="y:"+c3;
mat1="z:"+c1+" & y:"+c3;
mat2="x:"+a2+" &y:"+c3;

where c1,a2 and c3 are angle for row, pitch and row.
// for outer most ring
mat3="y:"+c3; // mean rotate around y axis with angle c3
// for inner most ring
mat1="z:"+c1+" & y:"+c3;// mean mean rotate around z axis with angle c3, then  rotate around y axis with angle c3
// mat2 is for middle ring

Click green triangle to generate new simulation when you finish your modification.

You can find the jar file,at [b]export[/b] directory under ejsworkspace

You will find "Upload new EJS jar file" at the same line where you submit the message , click the checkbox
then select your jar file with button, then submit your message.
Your simulation will be shown automatically follow the end of your message.