Discounting postage on buyer invoice

[orba14]

Hi
How do I discount postage on buyer invoice, when a buyer has purchased two items?
Thank you

[diecastcarsvicki]

go to send invoice 

delete postage cost then enter the new cost of postage but dont press recaulate and send then to check its right just look at invoice from sold page and postage should be fixed. 

[orba14]

Thank you 🙂