have just changed the van[pick new one up next week]and it's the 1st one i've had with a seperate header tank,could anyone advise me the best way to fill/empty the tank without getting the rinse all over the pitch,it has been suggested i use a watering can to fill it but there does'nt seem a lot of room.to empty there is just a yellow bung on the underside with no tubing,appreciate any help.