How to get Battery Acid off of pipe???

[Titanium]

So in my previous thread about my plastics breaking that caused my battery box to fall out making the battery hit the chain and blow up. now at the time it happend i didnt think about the battery acid getting everywhere so it got acid all over the inside of my red hmf pipe. how can i get these black marks off of my pipe. i can post pics if needed.

[the fat kid]

i guess post pics, and id also send them to maier to let them know you need a replacement pipe because of theyre defective product.