Replacing the cord on your dryer is very simple, replacing this yourself and not calling an appliance repair company will save you money.
If you have a new dryer or old replacing the dryer cord is straight forward. You need to have a simple understanding of how the dryer cord terminal block works. There are three wires that go to the back side of the block, (behind the screw that you are removing) each post has a separate wire.
Looking at the block from the back you can see a black wire on one side a red wire and white. Looking at the cord there are three ends to connect, if you lay the cord flat you will see there are three different wires wrapped in insulation fused together. One on the right, on in the middle and one on the other side. Connecting the cord to the back of the dryer keeping the middle wire on the middle the left wire on the left and the right on the right. Your dryer block has two hot legs that run on each of the outside screws and a neutral on the middle screw. If you have a volt meter you can confirm proper hook up before powering the unit on here is how.
On the meter you will have one red lead and one black lead. Touching the red lead to the far left screw and black lead to the far right screw you should have 220v. Testing from one outside screw to the middle you should have 110v and from the other outside screw to middle you should have 110v.