Procedure:
Loosen the cartridge attachment screws slightly, then put a record (preferably old and not too valuable) on the platter, and start playing it, so that the tonearm moves over the record and lowers onto the record. Then switch the power off (or unplug the turntable from the power socket). After that, the platter should coast to a stop with the stylus still on the record, and then you can align the cartridge, using a suitable alignment protractor (available free on vinylengine.com to download and print out – make sure it’s printed at the correct size), and moving the cartridge back or forward in the alignment slots on the headshell until it's aligned at both points (inner and outer alignment points). When it's correctly aligned using a protractor (any type, although I prefer Stevenson), tighten the cartridge screws, recheck alignment, and if still correct, play a record.
Unfortunately many older (last century) Luxman owner manuals were absolutely useless in describing exactly how to align the cartridge (i.e. set the overhang). Certainly the one for my Luxman PD-288 (introduced 1982) is, as were those for many similar models from that time (including the PD-277, PD-289 and PD-375). They leave you to guess how to do it, with just the barest hint in the manual that overhang adjustment needs to be done, and no description or diagrams of how to do it.
Luckily, I had several alignment gauges, and had a fair idea of what to do (having done it numerous times on many turntables), so I did mine using a Stevenson protractor, using the initial procedure I described above to lower the tonearm, and then aligned the stylus correctly at the two Stevenson alignment points.