--Updated--
Ok Calex Deus writes: "You only need to get to B10 kill the boss and then use the lift in the next area B11 on the left to exit. It's level 8 recommendation up to that point, then 20 for the next ones, so it's really easy solo."
This is what I originally did:
Solo guide - First attempt at dungeon.
With a level 26 Warrior I was able to make it through to level 29 costing me one revive when I was blown over the edge by a suicide bomber. Level 29 cost me one revive fighting the aliens. Then one revive on level 30 fighting the penultimate boss (A large Zombie) and then 10-15 revives on the final alien boss who teleports and blocks you off from attacking him with lightning circles (A tad unfair and cheap if you ask me).
I would recommend doing this with a group for the shared revives. Levels 1-28 pose no problem at all as you can run past 99% of the enemies.
Enemies do not seem to drop health ever and nor do most normal crates/barrels. I mainly only stopped to break the green barrels which 100% contain health items.
Total run cost me about 80-85 Happy Jewels maximum which were used to revive myself. Those were earnt from signing in daily as I haven't spent a penny on this title as of yet!