I don't have a TRX-1/2 I have the WS1080. So unless there's some NEW stuff added to those over my version ... you do it in the EZScan software in the CONVENTIONAL or TRUNKED tabs. Score the first line with your cursor/mouse, press, hold down the shift key on the keyboard ..... then score/click the last line you want to delete. It should have selected ALL objects in-between bottom and top, then press the delete button on the side. And when you upload your new form to the scanner all things will be changed.
That's odd. You click on the first line, hold the shift button down while that line's still scored blue or whatever color and making sure not to click anything else on the page... click the last line. All the lines should be scored in-between and be ready for batch editing. If you touch anything inside the page it won't work and you have to start again.