You need this tool to do it without removing the inner wing. I guess its possible but a pain.
When you have the inner wing on the floor, modify it so next time you can unscrew the section in front on the valve cover to gain access.

On mine it's actually a challenge to get the rocker boxes off without taking the wings off, and I've certainly never done it without dropping the oil everywhere. I am thinking of making some plates which bolt over a hole I'll cut into the inners next time I change the engine. If you can find a half decent set of ami inner wings I'll modify them for you to suit.

p.s - i bought a rear door for mine off ebay recently - turns out the gutter depth and captive nuts for the frame are different for a Berline - f**k!!!! that's what i bought....didn't think to check...another lesson learned

Yeah, I'm very suprised to hear that, I'd assumed they were all the same!

Join the club. I found out the same way when I wanted to move over the rotten window seals from scrap Ami 6 to our daily runner (Ami 6 1967). The Ami 6 before 1968 is not the same as after. The Ami 6 from 1968 onwards and Ami 8 do share the same doors. The clues are engine design, speedo pedal, alu trim around the doors