Solid tools save you a lot of time and – maybe even more valuable – prevent damage to the lenses. This page describes the basic set you’ll want to have ready when servicing vintage glass.
A set of good screwdrivers with hardened tips is the most important tool. Soft, breaking and grinding tips destroy the screw heads and should be avoided at all costs. I use regular Wiha PicoFinish with rotating caps, which perform very good at a more than reasonable price. The most common tip sizes in Minolta lenses are PH000 and PH00 Phillips, as well as 1.0 mm flat tip for tiny meade screws. A 2.0 mm flat tip comes in handy from time to time at various tasks.
On all Minolta lenses I have seen so far, lens elements are secured using locking rings. The name ring around the front of the lens usually is a locking ring itself. Locking rings typically have two opposed notches on top and a thread on the outside. Although it is possible to loosen the rings with two screwdrivers or a caliper, you are very likely to slip and scratch something. A spanning wrench solves this problem and should be your one and only ‘special’ tools to buy if you plan to disassemble more than a single lens in your life.
What can I say: Tiny screws everywhere. Tweezers with serrated tips make everything just so much easier.
The main tools I use for cleaning lens elements are an air blower, soft lint-free wipes and window cleaner. Camera manufacturers often recommend damp microfiber cloths for cleaning. I don’t use microfiber very often, because reusing a cloth always bears the risk of dust and fine abrasive particles accumulating on it. Cleaning with such a cloth then does more harm than good.
Also, microfiber may seem to wipe the glass clean of fingerprints and dust, but in my experirence often leaves an ultra thin layer of smear on the surface. The smear comes from the fat on your fingers being transferred to the cloth while using it. You can prevent both problems by utilizing each cloth only once per side and by wearing gloves for cleaning. Or by simply using disposable lint-free wipes. Slightly dampen the wipes with window cleaner for best effect.
As cleaning agents, I’ve tested ethanol, isopropanol, window cleaner and citric acid. In direct comparison, isopropanol (99.9%) really lets the glass shine the most at first glance. But it tends to evaporate so quickly, that you cannot dry-wipe the glass before the alcohol is gone. This leads to slight purple- and blue-glimmering residues on the lens surface. The same is true for ethanol, which performs even a little worse because it is usually less pure (94 – 99%). Window cleaner proved to be much better than originally expected: The water content and the small amount of surfactants keep it from evaporating too quickly, allowing a final dry wipe without any visible residue. It has become my first choice for cleaning lenses.
A fair warning at this point: Never, ever use acidic cleaning agents like vinegar or citric acid!
If you think about using acids, look left and see what may happen. Optical glass is a mix of crystalline organic and metal oxides. Some types of glass slowly react with acids resulting in the lens surface being destroyed and the lens going blind. I suspect, that the main reacting component is Calcium oxide (CaO), but I haven’t looked into it in detail. As you never know what type of glass a certain lens is made of, it’s better never to use any acidic fluid for cleaning.
On the net you will also often find the recommendation to use hydrogen peroxide (H2O2) for cleaning lenses or lens bodies. As this is a rather aggressive and dangerous chemical which will attack your skin and lungs and may blind you if it gets in contact with your eyes, I strongly discourage it’s use. I haven’t seen one single lens where isopropanol didn’t do the job.