Consider that the bigger the dish is, the more precise has to be its alignment. And probably done by a professional technician
There are quite a few hobby satellite members on the forums who have the skill to align large dishes.
If a large dish is single piece there are only two angles (Az/El) to set correctly for a fixed dish and three angles (Az/El/Dec) for a motorised dish, if azimuth is considered an angle.
This is fairly easy to do with a digital inclinometer and a reasonably accurate signal measuring device.
If the dish is multi-piece, such as 6 petals or more then the petal alignment also has to be taken into account.
For a 4.5m dish or larger that is multi piece then I agree that a specialist technician with laser mapping or some similar alignment device is needed, especially once the frequencies get up into the Ka-Band range.