I think that you should NOT cut it, because then the value suffers a lot if you want to sell it later.
The strap was also too long for me. I used my palermo Pm strap few times with eva, but I ended up selling Eva because it just didn´t fit for me..
So perhaps you should think is that the right bag for you afterall?
I wouldn't alter the strap, I think like other's mentioned it would be hard to sell that way if you had wanted to sell it later on. I like the long strap, but that's just me, I'm about
5'7". I would do as Christian's Girl suggested and look into the adjustable shoulder strap that LV sells. Good Luck!