How long would a garage charge to change the glow plug behind the fuel pump on an L series? I know the alternator, fuel pump etc has to be removed to do this one.

I've done the other three no problem and it starts 95% better but I want to get number 4 one too as the old ones didn't even light up when tested after I removed them so I reckon they may have burnt out, I've changed my relay too so hopefully this will have cured this little issue.

I've got the Haynes manual and am reasonably good with a socket set but not sure whether this one if beyond me ...

dont bother, REALLY dont bother! some l-series only have 3 anyhow!