I've got the parts to replace the group head gasket on my Elektra A3 and haven't been able to find any instructions/videos that describe the process (unlike the E61). Exploded views suggest that the old oring can be pulled out and the new one press-fit back into place--is it any more complicated than that? BTW I'll be replacing the shower screen and removing and cleaning the diffuser at the same time.

Thanks

Nope. It is just an O ring. Pick the old one out with a knife or other pointy object and push the new one back in. Easy as 1, 2, does not even require a 3.

Remove the showerscreen and the brass diffuser first unscrewing the screw in the middle of the grouphead (bottom/inside of course)
the follow Dave's instructions

Cool thanks

All of the above plus -If you haven't already done it, undo the three Allen bolts on top and pull the bell off. So easy to change the "O" ring gasket and even just for regular cleaning doing this.