I'm in the midst of restoring a 1st gen Europiccola. It's one of the later 1st gens with the removable shower screen. I've gotten the piston out no problem but am vexed as to how to remove and replace the piston rod seal without removing the group. I've read through many of the 1st gen rebuild threads and most people have removed the group or removed the boiler from the base. I hope to avoid doing either (so perhaps this is more aptly deemed a refurbish).

Any tips? Has anyone done this with the group and base still in place?

I have done so. It is a bit tricky to reach, but I put it on its "head" on a pillow and worked from there.

I have removed neither boiler nor group, but unless you have other reasons to do so, I doubt that it's easier than to overcome the inconvenience of reaching the rod seal with everything in place.

Apart from turning it in a comfortable direction, I have no particular recommendations. I did it without circlip pliers (they were delayed in shipment and I was impatient), but I recommend to do it with the pliers

EDIT: Ok. I'm sorry if I mislead you; I forgot you have the sleeve in. I thought your concern was the reachability even without the sleeve, but I don't know how bad that is with the sleeve in.

Done it many times without removing the group, if you have the sleeve out or it's a sleeve without the shower screen like a 73/74 you need a small pair or split ring pliers.

Turn it up side down in your lap with some good light and you can get the ring popped out and the washer and seal come out. I am working on a pesky 62 with a rusted split ring, have 80% of it out, got the washer and seal out...still going but I have not removed the base.

So it's patience and fiddling, I'll post the model of pliers I use in the am. Or you rotate the base, seems like work