Attention Thorens experts

I have a 100% stock Thorens TD-166 MkII with an extra arm wand. I had my current cartridge, an Ortofon OM-30 Super, professionally mounted. I assume the VTA was adjusted by the shop (a reputable local hifi store). I am thinking about putting a new cartridge on the second wand, probably a Denon DL-160. I am not very good at these things, but I think I did once mount a cartridge on this 'table (I've had it for 26 years, since new).

My question involves VTA adjustment. The owner's manual does not mention VTA adjustments at all. However, I see several philips head screws on the tonearm mounting plate. Are these used to adjust VTA? If so, how? If not, can the VTA of this arm be adjusted? If so, how? When answering, please keep in mind that I am neither skilled nor experienced in working on turntables or tonearms. Thanks!
It's not the phillips screws. They fasten the arm "board" to the subchassis. On bottom of the arm pillar you will see two allen headed set screws. One on the right and one on the rear. Loosen these to raise or lower the arm for VTA adjustment. Try marking the pillar location with a pencil or piece of tape before changing the height so the original setting is repeatable. Remember, you will also have to change the tracking force and anti skate for the other arm/cart. as well.
Dear Bondmanp: I'm not an expert on Thorens but I think that additional to what Hifiharv posted the section VIII on the manual could help:

Regards and enjoy the music,
Thanks, guys - you have been most helpful! Raul - that must be a service or dealer manual; mine does not have anything about VTA in it.