Not knowing which 150mm lens you have, not all are created equally. Some have screws under the rubbler finger grip strip on the sides, some have screws hidden under the thumb grips that get removed n access holes to the screws, the soft focus lens the entire front comes off to install disks n the access to the front cell is simple, floating lens style lenses need to disengage the floater lever n that will require realignment when assembling it again as well as clenaing all the elements inside the floater cell n relubing the helical, some lenses require removal of the name ring on the front n unscrewing the front cell like a light bulb. If you've seen enough of these lenses, you'd know by sight exacly how it opens.
Denatured methanol alcohol is the same stuff used to make shelac, sold in paint stores. There are other names for it in other countries, but here in the US, it is called Denatured Alcohol. Isoprople will do just as well AKA gas line anitfreeze. Denatuered means it contains certain other chemicals that are just as volitile as alcohol to make it undrinkable. the chemicals don't leave any residue since they evaporate just as fast if not faster than alcohol. Wearing gloves is recomended, it is toxic stuff and is systemically absorbed and will defat the skin which can cause long term damage. Good air circulation is also recomended regardless of which alcohol you choose you use. Vodka is not good and will leave a residue, it will only make your job miserable unless you are drinking it, then you won't care what the lens looks like in the end. Rubbing alcohol will leave a residue. Watch out when cleaning lenses that have edge blackening... it will disolve the paint and will have to be reblackened. None of the alcohols will harm coatings... an urban myth.
As for tools needed for lens work... only quality tools. Good set of screwdrivers is formost, good spaner n some mechanical intuitiveness. I made my spanners individually to fit the specific lenses I am working on instead of using an adjustable generic spanner. Rubber plugs, rubber straps, belt clamps, lens vice, 3rd hand, thread chasers n taps, micro drills, a few types of dental picks, hemostats, forcepts, scalple, q-tips, suction cups, screw organizers, a good loupe. Most important, a clean soft work surface n good light. Oh and having some great music going in the background so you completely forget what time it is.
