warm engine slightly, not hot
flip over the passenger seat
remove the oil filler cap
get under the front and locate the sump plug
undo and have a drain basin to hand.
remove rear service hatch
remove the oil filter
*tip by warming the engine slightly, it lets the oil drain quicker
*tip 2, get your fingers in the old oil! can you see silver flecks in it? too much = bad engine wear.

refit sump plug
fit new oil filter, dont forget to put a smidgen of oil round the rubber seal 1st.
fill with oil
turn engine a few times, top oil up...

same as my bike bar bigger scale!

manuals for these vans seem like rocking horse poo!
the only one i have (dealer manual) is for a diesel Hijet S85 VIN number, thing is my van is petrol!
But i am using the manual for reference... and i'll be honest.. it does NOT tell you where to find sod all! a basic knowledge of petrol engines and a degree in CSI investigating is a must!