well if u have a paypal account and they do too then were it shows the payment they sent it will show were u click ship package or somethin like that and u go down that page and put in the info .. like it will have urs and the persons address already on there and keep goin down and u put in the way u wanna ship which will prolly b first class since it will weigh less than 13 0z lol and u will put in the weight then scroll down and click pay and it will pop up on another page showin how much and everything and u make sure everything correct and u click pay and print walla lol also if they send u money to ur paypal but they dont have a paypal account then it prolly wont show that option next to the payment so if that happens then u will look too the right side of ur home page or w.e. and click shipping tools and click the link it gives u and u will put in their address and then click close or done or somethin and then u put in first class and the weight and it shows how much it is and u look at the top left and click print then another page pop up and click print .. walla ....
if it doesn print but shows that the money was taken out then u just wait for it to show that it was paid and click the details on it and at the bottom of the page u will see reprint u click that and u will print it like that.. but it should print the first time but if not thats what u can do