How to set up redding old style trimmer? 13 14 14k

[waltherboy4040]

I was wondering if anyone could explain to me how to set up a old style redding trimmer. It appears to come with a square blade and a v style shaped blade. Am I suppose to use both blades at the same time when cutting a case?

http://www.midwayusa.com/Product/344855/redding-v-cutter-blade-for-old-style-case-trimmer-13-14-14k

http://www.midwayusa.com/product/932811/redding-square-cutter-blade-for-old-style-case-trimmer-13-14-14k?cm_vc=sugv932811