The fuse for the front blower is located under the glove compartment, front passenger side. You need to remove 3 screws from the trim that sits in the footwell, right underneath the glove compartment, and then unscrew a large green screw that sits vertically - this will release the fuse box, which you will then need to pull down manually.

There is a map of all the fuses, behind a panel with a black handle, on the right hand side of your trunk (there are other fuses there too).

At any rate, most likely it's not the fuse, but an FSR - final stage resistor - it's a common problem in the X5 of that age - I went through this on my 09, while still under warranty.

In a more rare case, it could be the blower motor itself.