Easy.
1) Kill the first group and get a Arachnopod Destroyer ("spider vehicle")
2) Use Charged Leap to jump over the rest of the trash
3) Get on the tram
4) Aggro Mimiron and die/FD/Vanish
5) Have the raid teleport to him (since the teleporter is now enabled)
Please don't confuse this with the old "stealth to mimiron" trick. That has since been hotfixed.