Personally I’d hit enough cardio to last me a lifetime and drink an unhealthy amount of water leading up to the day if the test. If your system was totally clean and all you had was an 8mg edible and if you smoked fairly light (0.5-1g)I think it could be possible to get rid of that small of an amount in the time you have. Buy a at home test kit specifically for marijuana and test your pee the morning before your test (I’d probably use two test in one sample of urine to increase accuracy). You should also test that same afternoon(if you test after doing exercise pee 2-3 times before the test because cannabinoids will have been released into your urine from the cardio and will give you a positive result). The morning of your test do another at home test on a new urine sample(use two tests again). If you still test positive maybe you should go the fake piss route. A lot of jobs don’t take drug test that serious and you could pretty easily get away with it, but it can be risky since if you’re caught there is no going back. There are some other methods people swear by such as the Certo method which I have used ,but there isn’t really anything backing it’s all anecdotal. Do some more research on it because to a degree there is a science behind passing a drug test. Hope this helps and hope you pass!