Hide content in generated PDF (hide weight)

Hi chabis, we´d like to hide the weight data in the PDFs thru the functions of the plugin. We need the fields to be filled within woocommerce to calculate the delivery costs, so we cannot leave it blank there.
Any assistance where to change the code to get this working is very much appreciated!

http://ww.wp.xz.cn/extend/plugins/woocommerce-delivery-notes/