This may not be a problem:
We went round & round on this a while ago and the conclusion seems to be that if the beam:
- Goes into the center of the Mirror 3 opening
- Doesn’t hit anything inside
- Comes out through the center of the nozzle
- Remains perpendicular to the platform
Then there’s nothing to worry about.
Now, if you do have one of those problems, there should some screws holding the laser head to the X axis carrier in slotted holes that allow some angular adjustment. Two of them appear in the top photo on my blog post and there’s another on the far side; yours may be similar.