went to change glow plugs on grand scenic thought i would post some pics to help other newbies
pull up plastic engine cover
undo two bolts at top on right of the bigger metal pipe and there is also one on the right that bolts it to car
unscrew black rubber pipe at bottom and pull pipe off
This enable you to move metal pipe out of the way to lift up metal cover after you have undone the two bolts and unplugged the plug
this is what you should see now
all 4 glow plugs are in a line 3 are easily visible and the one on the left is harder to see but all are easy to get too just use smallest sockets,extension bar etc(i put a couple of arrows on a couple of them).
gently pull up plastic covers over glow plugs a helpfull thing to do when you have got undone is to use a bit of plastic pipe and slide onto top of plug and then you can turn that to finally remove plug and then do reverse when putting back in makes it a lot easier.
and then its the reverse of above to put back together hope this helps some other people