The IS-F is no different to any other car when it comes to alignment. Anyone with an alignment measurement machine and a spanner can do it.
Not all Lexus dealers have the facilities to do the alignment themselves, as a good quality alignment tool is very expensive. Getting alignment right is also complicated, and the staff training is also very expensive. Many just take the car to a local garage that does wheel alignment.
The only thing where it can get a bit difficult is that if the steering wheel is off and adjusted, the VSC system may need to be recalibrated. The garage doing the alignment needs a computer to delete the calibration from the VSC system, so that it can re-learn. Obviously, the lexus diagnostic system can do this. But, lots of high-end alignment machines come with software that can trigger a VSC recalibration on pretty much any car (even lexus). The alignment industry typically calls this process a "steering angle sensor reset" or "SAS reset" - so ask your garage if they can do this before taking the car down. Most should be able to do this, as it is an essential part of wheel alignment on any car with VSC/ESP (and all cars from 2013 MUST have VSC/ESP by law).
I'm not normally a fan of manufacturer sponsored "good garage guides", but you might want to check http://www.alignmycar.co.uk. This is sponsored by a manufacturer of high-end alignment machines, so it's not independent. However, I've taken several cars (inc my IS250) to random garages and to a couple of AMC sponsored garages. Both the AMC garages got it absolutely spot on, and it was obvious when talking to the tech that they knew exactly what they were doing. By contrast, a big tyre chain and a backstreet garage completely b*******d it up.
If you want to go it alone, then the best places to go for alignment, are either garages specialising in performance cars and tuning, or insurance-approved accident repair garages (these places do a *ton* of alignment checks as the damage assessment even on minor prangs)