ok, ive never replaced my glowplugs myself before, but ive decided to do it this time after having trouble starting in the cold, figured it would be pretty easy, right?

i pop the hood open today to take a look at it and it took me almost an hour to even find all of the glow plugs. each of the 5 is in a completely different position relative to its cylinder, not like the little picture in the service manual where theyre all lined up nicely(diagram of a different model).

i still want to do it myself though, i think.

i could use some answers to some questions, i know alot of you out there change your own plugs alot. if youve done this on a 2.5t before, i could REALLY use some advice.

first, what tools should i have?

should i replace them all, or just the bad ones?

and how do i find out which are the bad ones?

what parts do i have to remove to access all of the plugs and is it very difficult to replace them?

whats a good price on bosch plugs?

and lastly, is it just me, or do 2 of the plugs look bigger than the rest, at least from the outside? are these things ive spotted even the glowplugs?? i found them by followin the wires coming out of the GP control box on the driver's side of the engine compartment.

please help me out with all the advice you can spare, and thanks alot.

__________________
1991 300 D 2.5 Turbo, 220k
also in the family:
1981 240 D 185k
1991 350 SD 185k
2006 S 500
2005 SLK 350