Was over in Ireland a few weeks ago with the 45 at SWMBO's uncle's and as he has his own garage, and as I just happened to have a new glow plug in my glove box :p thought i'd ask his opinion on removing no'1 glow plug without removing anything.
He looked long and hard, got a hacksaw blade, cut the threads of the plug, got a socket set out (a very small drive one, so extension bar very thin), popped a socket on and out it came with a bit of fiddling, old one out, new one in less than 30 mins !!!!!!
Asked his opinion on no'4 as pump in the way, he looked long and hard, shook his head a lot, reckoned that was a challenge, but could have that out and new one in in about an hour, no dismantling and he'd do that when we came over next time.

Was well chuffed, and no charge :trophy:

Very interesting. I never managed to remove the 1st plug without draining the coolant, removing the coolant pipe, and loosening and then rotating the coolant elbow to allow access. With the right tools I guess it can be done without moving the coolant elbow.

For the 4th plug, I found the original fit plugs could be removed and refitted with light fettling of the plug, as the plugs were quite short. Chopping a couple of threads off the power feed helped to get an original fit plug back into the 4th hole. The new plugs I bought were too long, so I fitted a good original one back into the 4th hole.

If there was a source of glow plugs with a short power feed area then this could be a good solution to the problem of fitting the 4th plug.

I reckon #1 could be done with a deep 10mm 1/4" drive socket, which is something I didn't have (but do now) at the time of changing them, so I did as SDI_Tim says and rotated the coolant elbow out of the way. As for #4, I'll leave that one well alone - mine started OK with 3 dead plugs, and I suspect the 4th is dead too - so a 75% improvement ought to be just fine :lol:

If I'm ever unfortunate enough to need to remove the pump I'll make sure I buy a plug then, but until that happens it's staying put!