html/admin/order/pdf.php
data/page_extends/admin/order/LC_Page_Admin_Order_Pdf_Ex.php
data/class_extends/page_extends/admin/order/LC_Page_Admin_Order_Pdf_Ex.php
data/class/pages/admin/order/LC_Page_Admin_Order_Pdf.php
data/class/SC_Fpdf.php
関数 SC_Fpdf
この辺を探れば比較的簡単だ！