Replacing fuel tank breather lines..

Hey guys,

I need to replace the breathers on my fuel tank. see items 2 and 3 here

http://www.realoem.com/bmw/showparts...41&hg=16&fg=05

The original items have rusted badly and are now dispensing my precious fuel all over the tarmac if I put more than 4 gallons in the tank.:(
Probably due to the fantastic British weather.

I was wondering if anyone had carried out this procedure themselves and could offer any advice. I'm thinking it could be a pain to due to filler neck fuel lines etc.....

Any help would be gratefully received........ Thanks