Unless you are a Muslim you are not allowed in the Mecca city limits.
Yup,I'm aware of that.What I'd do to prepare is to go to some mosque far from where I live and say I want to become a moslem.I'd also tell a few other lies.Then,I'd get a letter from the "imam" saying that I've converted.
If I'm challenged at any point while in Saudi I'll say that I'm a new convert.
I know I could get into serious trouble but I'm willing to take the risk
And BTW...if I succeed in entering the city I'd stay no more than an hour...and probably less.
"Burton's best-known achievements include: a well-documented journey to Mecca in disguise, at a time when Europeans were forbidden access on pain of death...."
Fascinating character...more at:
https://en.m.wikipedia.org/wiki/Richard_Francis_Burton