Some people have done it already. Poachin for one, as @LuckyLook said, as well as @House M.D. and myself. I don't know if anyone else has, but I can imagine some others soloing Zak (@DomoLovesPie?). It takes 60m mesos or so. Might also add that it's pretty annoying without a Bishop of your own or duo with a Bishop for arms, unless you're really funded. I did it solo (only used Bishop for HS) and Apple'd for arms at a 8k clean range. Took me about 1.5 hours.
GEN20 MONEY PLAN. GO IN WITH YOUR BISHOP TO CONSTANTLY GENESIS THAT UGLY BTCH. YU BSTEP THE 2 RIGHT TOP ARMS. THE TOP LEFT ARM YU CAN HIT IT WITH ASSASSINATE IF YU AIM IT RIGHT. BUY TWO APPLES TO SPEED UP THE PROCESS. THE OTHER ARMS YOU CAN BOMB. YOU SHOULD DO IT WHEN YU HAVE AT LEAST 7K RANGE CLEAN. SO LEVEL DOES MATTER.
In all seriousness. Don't try to solo Zakum when you aren't a Shadower yet. You don't have the necessary skills to hit the top arms.
^ In fact, I wouldn't do it without having Shifter and Smokescreen maxed and 6k+ range. I had a 12k buffed range and it still took me quite long, I think 6 minutes per arm (and hitting several arms at once)
It took me 53 million mesos to kill the body using ME, dropping 5k bags. It took 1 hour 30 minutes. If you want faster results you will need to use more meso. Anyways as people above pointed out, your problem is not the body, it's the arms. The top 2 arms have the most HP, and you can't hit it with ME or SB. What you might wanna try is teaming up with a BM or a Corsair and doing a 2-man zak. BM takes out the top arms, you meso explode everything else.
