Ok I have done this a couple times and have been very happy with the results of the job. This is how I've done it. First thing I always do is sand the lens down with1000 grit or finer sandpaper depending on the condition of the lens. This ensures any imperfections and defects and any other crap that's on the lens to be removed. Once this is all done your lens will be scratched all up and you should not be able to see into it or it should have a cloudy finish. Depending on what grit I start with I usually end up going over at last with 2500 or 3000 grit. Once the sanding is done, clean the lens thoroughly. Next I buff out the lens. I'll use a rougher compound and go over the lens a couple times and then I'll progress to a fine polishing compound. Once I am done the lens should look brand new perfectly clean and perfectly crystal clear. This is where it gets crucial. Clean all the compound and everything else off the lens very thoroughly. When thats done I'll use a degreaser/wax remover to wipe off the lens extremely well. Now because I'm a painter and have this stuff laying around it's easy for me to come by, although it's not hard to find a any auto store. This is where the spraying begins. The VhS tint goes on dark as a warning. Within 3 coats the lens will be extremely dark and hard to see through unless you have a very bright light bulb. Apply the first coat very thin and as evenly as possible. The spray will actually dry fairly quick but it will not be too it's completed darkness right away it will darken more. I learned tje hard way. I usually let each coat sit at least a half an hour or more before applying the next coat. That usually gives me a good idea how dark the lens will be at this point. Then from here on out it is usually apply another coat letting it sit for at least a half an hour between each coat until you get your desired darkness. Once desire darkness is achieve let it dry and completely set up before messing around with it. Now depending on what look you want the VHT tint is actually a matte black finish or a flat black finish. If you want a gloss finish there is are additional steps, if you want the matte or flat finish you are done. For the gloss finish what I usually do is after you apply your last coat of tint and let it sit for a half an hour I will then apply a clear coat over the black to the desired gloss finish and let fully dry. Only, and only if you use a clear go finish, from this point if there's any imperfections or dirt or anything that got into the paint you can sand and buff again to get out the imperfections. That's about it your lenses are now done. The crucial thing here in all of this is making sure that lenses absolutely clean of any oils, wax, grease, solvents...etc. of any kind to make sure that the VHT tint sticks to the lens. If it is not you will have fish eye, peeling, and cracking up in the finish of the lens and it will not turn out very good. I hope this helps.